Hello quasimodo,
Hmmm.... I'm usually pretty careful with accidentals. On your point of my missing the accidental on the last note, in the Paderewski Edition, which is highly respected, the g flat in the RH is made natural to g--which is exactly what I played there Also, the editors' commentary makes no special reference to that g natural. Are you, perhaps, looking at another edition where that note is played as a g flat? I suspect that what Chopin was employing there was the Picardie Third device, so favored by Bach, wherein the minor third is raised to the major third in the last note or notes of the work. This brings about a sudden and unexpected burst of brightness at the end of a piece in minor mode.
Yeah, actually I recorded the piece at home, so just casual comfortable clothes, and my shoes were off too. But my rendition, which is taut and has a quiet intensity, does need to breathe a bit more, I agree.
David