As for the large chord... Play the Db and Eb both with the thumb. Handy trick for large chords that have a little cluster at the bottom.
In pieces like this the horizontal continuity of rhythm is more important than the vertical alignment. While theoretically the way you illustrate is how the notes would line up, you probably may not wish to rigidly follow this course. Phrasing and direction of line take primacy, and to have them free flowing often means slight modification of rhythmic alignment.
I don't play any finger substitutions in the LH. Just stretches throughout the entire piece. You don't have to play finger legato in order for the LH to sound legato. Finger substitutions may hinder the flow of the accompaniment. Remember it is the RH that has the melody and that is where listeners attention will mostly be. Try some of these:321244 551255 321254 51 (RH 1) 125
I see...So how would I figure out when to play the sixteenth notes? Right now I'm practising at a really slow tempo, so I have find some place to fit that note in...
Thank you for your suggestion but my hands still can't quite reach all the notes in this chord. Maybe in a year, my hands will grow bigger. For now, is there any other way I can play this part...
Another way of thinking of overfjell's suggestion is to treat the Db and Eb as a grace note tied to the rest of the chord. The other way is to roll the chord. But this option may take away from the intensity of the passage.
If you can't reach the notes with the thumb on the Dflat and E flat, strike the Dflat and Eflat then as quickly as possible, strike the rest of the chord after, not like an arpeggio, but more like two rapidly alternating chords.
For practice, just fit them in as you illustrated. When you are getting more into the interpretation stage of your practice, you need to think of where the melody is going and how the phrase ebbs and flows. You will be concentrating more on the shape of the melody rather than the alignment of notes with the accompaniment. Ask your teacher to demonstrate the shaping of the phrase. Another thing to do is ask a vocalist to sing the line for you. Chopin adored opera, and many of his melodies are inspired by song and singing. It may be good to note that in Chopin's time it was a notational convention that the vertical hemiola of dotted eighth and sixteenth against triplets was a shortcut for writing a bracketed triplet of quarter + eighth. Personally I do not play it such way in this piece but it is good to keep in mind when forming your interpretation. Another way of thinking of overfjell's suggestion is to treat the Db and Eb as a grace note tied to the rest of the chord. The other way is to roll the chord. But this option may take away from the intensity of the passage.
Thanks, I guess I'll have to do that for now. Do you have any fingering suggestions for that? And would I play the first chord with the bass, or before? Thanks for all your advice and help