Introduction of Chopin's G minor Ballade

[caters]

I am unsure if what I have so far of my analysis is correct, so I thought I would ask you guys. It's just the introduction I'm having trouble with. This is just one of many examples for my music theory book of applied chords, specifically V7/V(which appears in the Moderato after this introduction).

Here's what I have analyzed so far of the introduction:

[mad_max2024]

I'm more used to Jazz analysis so won't know the proper cypher and language but that N64 feels like a bVI(#11) to me (or whatever the classical cypher for it is).  A neapolitan would have Ab instead of natural (and first inversion).
I think I would also likely class the V that follows as a minor v if I wanted to give it a chord symbol.

Though tbh, I'm not sure if Chopin is thinking of chords there. I think it's more that he goes F#-Eb-D using minor scale melody between them.

[caters]

I think I would also likely class the V that follows as a minor v if I wanted to give it a chord symbol.

I wouldn't, because, at least in the common practice era, which includes Bach and Chopin among others the V chord is almost always major, regardless of if the tonic is major or minor. Minor v, I have seen, generally in chromatic or otherwise descending progressions, or just for the sake of some chromaticism in a major key, but I see major V a lot more so I always err on the side of major unless I see that minor third.

[mad_max2024]

That's fair

I just struggle to hear it as a dominant and when I try to harmonize it I feel v sounds more natural to me. But I can see it being V too if you hear it that way.
v would be the v chord of aeolian which is fairly common nowadays as modal interchange, though probably a lot less so in Chopin's time. V is, of course, the dominant of minor.

Like I said, I don't think he is even thinking of chords, he's just ending a melody line in the 5.

[lelle]

My perception of this intro is that it's the N6 as you wrote for the first two and a half bars, and then on beat 3 of bar 3, the G is an appogiatura to the F sharp, and we are on the V, not the i. Progressions involving N going to the V are common as the N is used functionally as a variant of the iv in the common progression of iv -> V -> i.

Bar 4-5 are just the V being decorated (notice how he is just circling around the main chord tones of the V, first F sharp, and then D). Beat 4 of bar 4 is not an N since it's an A natural and not A flat. I could concede that the A-G on this beat could be perceived as a resolution to the i (or the Submediant, considering the E flat), but then it goes back to the V on beat 3 of bar 5 as you wrote.

In bar 7 you have an error, there should be an E flat on the top note in the left hand, not a D. Since there is a D in the bass, I would perceive this as a "chord appogiatura" to the V ( G Eb Bb -> F# D A) or similar, something that's leading up to the V in the next bar (not shown in the image) which finally resolves to the i. It's definitely something dominant-y and not an i64.