I want the musician to feel the music and express himself through the music in a way that feels comfortable to him, the way that the music speaks to him. If this own interpretation is a bit slower or a bit faster than the given metronome mark, I don't care. (...)
This is basically how I feel about metronome marks. It's one tempo that the composer feels that the piece could work well in, but it's not the only possible tempo.
Being a composer too, I can relate to that. About fifteen years ago, after having played Beethoven, Mozart, Schubert, Chopin etc for ten years, I started playing jazz and other light music and indeed found that with improvisation I got much more freedom and could express myself through the music more easily. All of my pieces are in essence, improvisations and not defined notes or tempo. I even had problems to define the melodic lines, since these would change depending upon my mood.
Indeed, a lot of (what we now call) 'classical' music and undoubtedly also Chopin's, was created through improvisation (I love to improvise on the chord schemes from many 'classical' pieces, but of course this is another story).
So then why should we keep so rigid to Chopin's markings (or notes)? I guess simply because that's what he wanted. Why else would he have written the scores so detailed. Every rest, every accent, every melodic line is specifically noted. I you look at the details of many scores it is unbelievably specific in every respect.
This doesn't give the impression of coming from someone who wants the musician to 'express himself in a way that feels comfortable to him'.
That's why I'd be very cautious to change this assigned tempo. It might be more of my taste and it might even make the etude loose 'a little bit of it's effect', but it's not what he wrote down and (I believe) he would have wanted.
(Of course that is only my humble opinion. That's the beauty of music. Anyone can do whatever feels best to him or her.)
