Thank you for posting your interesting interpretation. The piece is a very old favourite of mine and is always a joy to listen to and play. It is a rhapsody, after all, and the solo version offers great scope for legitimate personal variation in ideas.
I think it would benefit from less pedal (except with the big theme of course - that needs it) and a touch much closer to that of staccato rather than legato. Gershwin himself stated that his music in general required a detached touch entirely different from romantic legato. You don't play it too fast, which is a pleasant change from some ninety-miles-an-hour recordings I have heard. I think the section immediately after the big glissando needs work. The only way I can ever play that part, which took me ages to get right, is by imparting what amounts to a strong rumba rhythm in the cross-over figures up in the top. That is to say, accent the left hand
1 - - 1 - - 1 - where the 1 is what the left hand does. My teacher, who often played it in public and with whom I studied this piece many years ago, gave me that tip. Unfortunately Gershwin's own rendition on piano roll is no guide for this bit because extra notes have been cut in the roll.
The other thing which my teacher used to emphasise was the need, at all costs, to avoid making those reverse basses in threes - quaver chord at the top and crotchet fifth at the bottom - sound like Gilbert and Sullivan. If they do, then the whole thrust of the rhythm disappears and it becomes a sort of waltz or 6/8. It's hard to explain what I mean but would be easy to demonstrate.
I like your opening, again because it is unhurried and very clear. I like your interpretation of the staccato "railroad" section, all too often turned into a mad rush which loses the rhythm. Thank you for posting your playing of a wonderful piece which cannot have too many interpretations.