All right, I'm following along now. I'll try to give advice on everything I can think of as I listen through the piece.
Ominous, yes, I think you did pretty well with that. Some basic comments on that section that I think will help.
Starting in the second measure, with the repeated Ds, you should phrase them somehow. You don't want it to just be the same volume and same tempo or it becomes monotonous and boring. You did a very slight rit. towards the end, then delayed the C-c just a tad, that was nice. But try to shape all of it more. I think the climax of that phrase would be on beat 3 of the 2nd measure, so think of it like the 16ths are leading to it. Maybe speed up very slightly into the 3rd beat while crescendoing, and then taper off after the first 8th note. Try singing the thing to help you, like...
da da da daaah daaah daaah daaaah dum
Then, measure 7-9, try leaning into beat three, like beat two is rising to it. And then, I liked how you leaned back on measure 10, that's exactly what I'd suggest doing. Although, maybe take a little time after beat two before going on to beat three in that measure. If I had one piece of advice for this entire piece, it'd be "Take more time!", not "play slower", just have points where you let things breathe for a moment before moving on.
And for each of those sets of triplets, crescendo into the downbeat. And for the d d d-flat picking up into measure 9, I think you should take just a split second (not very much, don't overdo this!) of time after the d-flat before you play the downbeat. Let people lurch in their seats a bit as they hear it.
Then again, don't be afraid to take time after measure 10 going into 11. The style changes completely, it's weird if you just blast through the change as if nothing happened.
For the section starting at measure 11, tone the volume down. It's way too loud--the piano has a harsh sound at the volume you're playing it. It should be more lyrical, I think. Keep in mind, my interpretation is based only off the score and what I'd do--I've never heard the piece other than you playing it. So, the left hand should back off more, and the bottom notes in the right hand should back off too (I know it's hard to play different volumes with different fingers on the same hand...took me forever to be able to do it, and I still have trouble in certain places, but do your best. It helps if you slant your hand so your pinkie or whatever finger is playing the top notes is more under the weight of your hand proper so you have more weight behind these top notes). So the melody in the first 4 measures of this section should go C E-flat D C B-natural C D C. Notice how in measures 13-14, your playing sounds like B C D chord. The top note of that chord is C, which will complete the line. The E and G in the chord are of minimal importance. As for the melody in general, it needs to have form. It should start a bit quieter and rise to a climax, then taper off. Without having played around with it for a bit, I'm not sure what the best spot to put the peak would be, but I would guess the B-natural would work very well. Play around with it for a bit.
It doesn't sound like you're using much pedal there, you can use more, but don't let it get blurry.
Just want to reiterate this, left hand is too loud and monotonous. Just like the phrase in the right hand, your left hand should have shape too. I feel like it's reaching for something. Like, starting on measure 11, it grabs, but misses and falls, 12, grabs a little higher (so play a little louder--a /little/--subtlety is key with all this stuff...it just sounds stupid if you overdo it), then 13, it goes down again. Then in measure 14, as the notes rise, let the volume rise, up to the A-flat, then momentarily fall just a little...you're reaching for the A-flat, fall down a little but keep rising to the B, then fall down on the following notes.
Measure 20, you return to that same melody in measure 11. Take a little time, just slow down a tad going into it at the end of measure 19. Again, not too much, but a little.
As far as the rit. goes in measure 25, I think you should start it sooner. The section is clearly dying starting around measure 23, so start to back off a bit, slow down a bit but not a ton, and then in 25 you can make a point of really letting everything die. Notice how the left hand's high note is the C in m23, and then it falls down into nothingness.
Measure 26 through 39, you definitely need to be more graceful. It sounds like you're really struggling to play the notes, probably because you are struggling to play the right notes. Perhaps you aren't technically able just yet to get it to sound graceful, but you should definitely make an attempt. Slow it down, be very legato. Practice with a metronome. I don't know what else to tell you on that. Overall, the right hand needs to be much lighter and smoother. Currently, it sounds like you're playing "E flat F G E flat F G A flat F G" etc., but in phrases like this, it's not exactly about the individual notes. Bring them all down, and let the notes "flow".
For the octaves in that section, yes, you're definitely going to have to use pedal to smooth it out, but at that volume and speed, it can easily become blurry. Be careful to clear your pedal very often (maybe every 2 notes, even? Experiment). I'd say the problem with the octaves isn't the volume. Between the hands, your left has the more interesting part here, and I thought the volume you played your left hand was appropriate, although your right hand should come down in volume some. The evenness and chopiness are the problems there, and that can only be fixed with slow practice. Make sure your wrist is very loose and you feel no strain in your hand as you play. Being relaxed will help make it less jagged.
You return at the end of this to the beginning. You need to make sure you don't take a break there. I'm guessing you broke due to difficulty playing the notes into it and not as a musical choice, but either way, you should crescendo into the repeat. I've been told you should never play something the same way twice in a piece. You don't want to play these 10 measures the exact what you played them the first time because it's not the same. It's like, have you read the Hemingway story "Hills like White Elephants"? They're at a train station. Girl is pregnant, guy is with her. She didn't want to get pregnant. They're talking about an abortion. She looks and sees hills ("like white elephants") on one side of the tracks and says, "See, this is what I had, this is what we had, and now, it's gone, and this (gesturing to the barren land on the opposite side) is all we have." And the guy is trying to convince her to get the abortion, and how after the baby is gone, things would go back to the way they were. But she says, "No, they'll never go back to the way they were. We can go back to what we had before, but it won't be what we had before. It's changed." Anyway, long tangent, basically saying that sh*t's changed since you played these 10 measures the first time. This time around, raise it up at least one dynamic level, maybe even take it a little faster, but not tons faster...10 bpm more maybe?
So that first note needs to be lllllllllllloudd. It is everything you were working towards in that long brutal 16th note passage.
Now the playing. As I said, needs to be different. Think of it this way. The first time was a question, this time is a statement. Reflect that in your playing. So, I said earlier you should play this part faster this time. Try not only playing it faster, but accelerating while crescendoing, keep going, rising into measure 7, that last note is your climax, then relax back...not quite as relaxed as you were the first time around, but play measures 7-10 at the tempo you started the repeat at, maybe. When you hit beat 2, decisively drop the volume, but not completely, and let these 4 measures act as the section dying off. Come measure 10, really let the section die before going to the coda.
And as you're crescendoing into measure 7, do not be afraid to get loud.
Next section, nicely executed, I liked it. Play lighter. And then, hmm...I'm thinking about how I think you should articulate this. I think you should articulate the right hand like this. Beat 1 is staccato, then the first 8th on beat two should be slurred to the second 8th on beat two, which would make the second note staccato. Try leaning into beat two a bit, and pulling back on the second 8th of that beat.
Then copy what I said for beats 1&2 and apply it to 3&4.
The syncopation on beat 4 of every other measure needs to come out even more, I think. You clearly accented it, but maybe just a bit more. It really needs to throw the listener's balance off.
Measures 44-47, really liked what you did with your left hand. Really nice sound.
Measures 48-51, back the right hand off. We've already heard the right hand's part 4 times. It's become the ostinato, nothing interesting happening there, so back it off one full dynamic marking, I'd say. Then the left hand, even louder. It has a really sweet part, and you need to let it shine. If there's one thing I love, it's left hand melodies, cause the bass register just really thumps your heart. So really lay into your left hand. As for articulation, I'd say all the notes should be stacatto except add a two-note slur on beat four of measures 48 and 50, and then slur the 16ths in 49 and 51. The 16th notes supposed to have a sort of sliding feel, like a trombone sliding down to a low note. Make sure they're very smooth (which you did) but also louder. It sounded like you sorta faded off on them, which I didn't like.
Now, for the entirety of the section, you're dealing in two measure increments of basically the same thing with some more notes added in each time. Each time you repeat the right hand pattern, the entire sound of your playing should be noticeable louder than the time before. You're building up here. And measure 51, really push it over the top. Measure 52, lay into those chords. You just sorta "played" them, but, like measure 1 on the repeat, measure 52 is what you've been building to. You never really got to much of anything in regards to volume there.
Then, measure 58 or 59, you backed off, very nice. Measure 60, I liked what you did there, building up, and then on measure 62, I'd say you should do a quick and decisive rit. beat 3 of 62, and really break out of time waiting for beat one of 63. Then 63, a tempo. If you're not opposed to modifying the score a bit (and really, you shouldn't be, since you're playing an arrangement anyway!) and you like the way it sounds, I would have the left hand play the same thing the right hand is playing in measure 63, but obviously, two octaves lower. Still play the B as written, bet on beat 2 try going down 2 notes to a G and follow the right hand. Of course, you don't have to do that, but I think this is a really powerful section, and you're definitely not getting enough power out of it. Crescendo into measure 66, constantly building, and start slowing down around the start of measure 65, I'd say. Then measure 66 with those two chords, really play them, and take time between them (but hold the sound with the pedal!). The triplets were wayyyy too fast. Start them much slower, and continue slowing down till they are /very/ slow. Then beat one of 67 is played, and beat two should feel like it's being pulled back, or laying back...a bit quieter, held a bit longer. Then release. Measure 68 a tempo.
I don't really have anything new to say for the next section there, just the same things I said about the first 16th note passage basically.
I see you mentioned the jump at the beginning of measure 62 in your comments as well...it sounded fine to me, maybe try to get it a little faster, but I didn't even notice it as a serious problem. To make it easier and faster, try fingering the last 3 triplets of 61 in such a way that you end up with your 1 on the D.
All right! Well, I hope that's been helpful. It might not have been exactly what you're looking for, but doing all or even some of the things I mentioned could really bring the piece up a lot, I think. It looks like you haven't learned the entire piece yet based on the score, so keep chugging away and see what you can do.
On a side note, I'd really suggest you start taking lessons. You've obviously put in a lot of time into this and it's sounding good, but your playing could become a lot more musical with some direct guidance (which I tried to give). Most of the things I've suggested above are things I would do without thinking about it too much, they're just natural things I'd do. All these things are picked up in two ways: through someone telling you to do them, and by hearing others do them. So getting a teacher will help you musically by telling you exactly what you should do not only technically, but musically, and then listening to lots of music, especially classical piano music, will help you make your playing more musical and natural feeling.
Good luck! Keep us (or me, at least) updated