For the Chopin:
1. The speed is probably good as a "performance speed", but it seems like there were a variety of careless mistakes, so it might be worth it to slow it down and work on those (such as at 0:16, 0:26 where it sounds like some of the notes didn't come out, 0:46, 1:00, and others ) and then bring it back up to speed. Although yes I know it's a live recording (I make all sorts of errors that I never make as soon as I turn a camera on!) so it may just be that.
2. Roughly at 0:36 or so, you play high Ab notes with your right hand, although I think they're more commonly played as Gb notes (or at least, that's the way I learned it, though on Youtube people do have different notes there).
3. I think overall the piece is played too loud with the pedal overused, although this may just come down to your recording device and my personal interpretation of the piece. I feel the right hand should have a very ethereal (astral, airy, flighty, etc.) feel, yet at the same time very crisp and brilliant. The best exemplar of this is probably Vladimir Horowitz's rendition found
here (though is he stifling a yawn at 1:20?). Although a bit of a sidetrack, the
music from hyperspace from the game Star Control 2 represents the feeling I have in mind the best I think, during 0:15-0:45 (to give you a frame of reference, it's the music that plays while your ship is traveling in hyperspace in between stars). Using less pedal would let the notes come out more rather than get washed out; you could also use partial pedal to have a sustaining effect but not overpower notes being played. In contrast, I think the ending is one part where the pedal could've been used.
4. It doesn't seem like there's a lot of volume contrast, although again that could just be due to your recording device. As mentioned above, the second measure is marked piano, a contrast to the first measure's forte, and then it gradually increases back to forte when the theme is repeated (and then back to piano). The middle section should be noticeably softer.
For the Rach:
1. Although the beginning part probably is a bit too fast, the bigger issue I think is that there should be more rubato. For example, I think there should be a slight (slight! not too big) pause before the three 8th note chords (i.e. after the low C#) to make the low melody more dramatic. Also, it should have more phrasing; for example, for the three 8th note chords, I prefer the second chord to be slightly louder than the others, and when the low notes switch to C -> B -> E it should be somewhat louder than previously. These are more interpretative suggestions though which will vary by pianist. You can hear Rachmaninoff's own take on it
here, although you shouldn't feel obligated to follow his interpretation precisely.
2. In the transition sections (such as at 0:43 and at 1:08), be sure to clear the pedal very often, after every 2 chords or so. Otherwise the sound gets muddled very quickly.
3. Some of the notes sound wrong, but it's hard to tell if those are careless mistakes or the way you learned it. For example, at 1:22, the right hand is supposed to play (F# B# D) but you play (F# B D) instead. That ends up changing the harmony significantly because it basically ends up as a b minor 7th rather than a D dominant 7th. Also, at 2:36, for the second of the three 8th notes after low melody C->B->E, you play D (natural) with your left hand rather than D# as written. Although this might depend on the edition you got; the edition I learned it from had D (natural) in the initial part (measure 6) and then D# in this part, which I liked because D# makes it sound a bit spicier to my ears (and provides even more contrast of this louder section compared with the quieter initial section).
4. For the middle section, again be aware of overpedaling. I would recommend partial pedal for it so that you still get the rich harmonics but without the pedaling drowning out the notes that you're playing. Be sure that the first note of each triplet can still be heard clearly through the pedaling.
5. Pay attention to the chords at the end, it sounds like some of them are played incorrectly.
6. For this piece, I'd recommend memorizing it when you can. Once it's memorized and you can focus your attention fully on your hands rather than on reading the score, the piece can become much more vivid and expressive. Although it seems like you're already not using the score most of the time (i.e. it's just there for moral support).
Overall both pieces already sound pretty decent, I'm just being nitpicky because I've played (and performed) both of them before so I'm more aware of their trouble spots. Good job, and welcome to Pianostreet!