I played this piece last year, so a lot of this is from experience/my teacher. Also sorry if it seems dumb, or obvious, or sounds like an adjudication - I am not skilled at talking about music.
I love this piece! Very difficult though, musically! You have to create the Russian choir, the dark church, the bells, the mist. Of course Rach/Moisevitsch called it "The Return" but to me it sounds like a funeral .... here are some suggestions:
i) your pace isn't too slow necessarily, but the problem is that you are holding the tied melody notes too long - try beating time one-two-three-four to the bar and you'll see what I mean. This will help fix your pulse. (Like CPR!)
ii) bar 11/12 - be more free and improvisatory here - the repeated motive is growing longer and more impassioned here - think deep Russian basses. (although you don't have to speed up much - save that for the poco piu mosso). Bar 12 - the top LH G-natural needs some emphasis for contrapuntal reasons. Don't be afraid to roll that chord - its much easier, and the delay emphasizes the G nicely. Bars 11-13 should be more continuous.
iii) bar 14 - more motion - carried away by sadness here, but very smoothly - no sudden changes of tempo at the begininning or end of this section.
iv) bar 19 - When the dotted rhythm appears in the accompaniment triplets, the F# in your recording stands out too much - it is the E before that which is stressed. in this section, try for more melody, less accompaniment. Your 'choir' is only singing the melody. These inner chords are just sustaining, resonating. Also, at "Tempo I" start softer and BUILD through this section - it's soo dramatic, saves energy, --- building the accompaniment gradually will help you with this.
v) l'istesso tempo - here you need to balance and project the outer AND inner lines! This is the hardest part of the piece to me, esp. w/the double notes. Watch the rhythm again - sometimes you are clipping the 16ths and making them 32nds. Bar 42 - grow, with a feeling of terrible excitement ... Also watch bars 43 and 44 - the new rhythm on the 2nd and 4th beats: the double notes continue one 32nd after the upper voice now. Try to show that more, even if you don't take it in strict time (the skips to double notes are hard!)
vi) bar 46/47 - last/first notes in the LH across this barline are stressed - maybe hold back a touch before falling into the cadenza to emphasize. It's the main melody notes, condensed - this is a climactic moment, a passionate outcry, &c.
vii) bars 59/60 - the idea of a B major chord transforming into B minor occurs twice here - a ray of hope appears and then is quashed (twice). Heart-rending. Make a decresc from the first to the second chord each time (and an overall decresc over the two repititions) - the effect is tragic. It sounds like you are already drawing attention to the "minorness" (lowered 3rd) of the second chord. Good job.
Also, check bars 57/58 - it sounds like you played the wrong bar by accident? Or maybe it's just late at night and I have class tomorrow....
Great job - record and post it again sometime...
Sorry this post is so long .... this piece is not easy, yet so worthwhile.