I saw Pollini play a few months ago, and he used the soft pedal a lot. But when he wasn't, he put his left foot under the bench.
I almost never use the una corda pedal. Which is probably a good thing, because I think I still have a long way to go on mastery of the sustain pedal. I like to think that I enjoy the challenge of making soft passages sing without it, but that might just be one of those things I tell myself.
By the way, Monica...I noticed you wondering a while back if Gould played Chopin, and though you might have already looked it up, Wikipedia quotes him saying that he played Chopin once or twice a year, "for himself", but that it "didn't convince" him. I can certainly understand his appreciation of the things in Bach that are absent in Chopin, namely strict counterpoint. With Chopin, counterpoint is rarely so strictly defined - rather, it's implicit, with the way that Chopin voices his chords (usually quite perfectly). As much as we love Chopin, much of what he wrote can be easily used as an accompaniment to yet another melody that intertwines perfectly with both the existing melody(-ies) and the chord voicing. Even a simple mind like mine could probably easily come up with something beautiful and profound that would move through those gaps, with what is already written acting like the banks of a river.
I've actually thought about doing that, with the concertos. Not sure if I've mentioned that before, but it's something I've been thinking about a lot with this recent renaissance of love for the concertos I've experienced.
I wouldn't change the slightest bit about the piano part. Chopin was in his element writing for the piano. But it's pretty obvious that he didn't really put a whole lot of love into the orchestrations. The harmony is perfect, and there several submelodies that have his name clearly written on them, but he didn't get too adventurous with it. So I get to thinking, wouldn't it be cool if I could transcribe, and embellish, the orchestral parts for a string quartet? That would turn the concertos into quintet sonatas, but I think it could be awesome...Chopin was certainly capable of doing such a thing for himself, but he wrote these concertos at a very young age, and I think he probably used them as a part of his purchase into the music scene. Keyboard music was not at that time nearly as popular as the larger-scale sort of music, and chamber quintets don't quite hack it either. Chopin made his name known fairly quickly, and then essentially retired from the stage and made a good bit of money teaching piano lessons. The wealthy youth in Paris and the surrounding area were I'm sure quite willing to pay exorbitant prices for his guidance, and there were probably quite a few talented ones, too.
So, no more torturous orchestral scoring projects. I can imagine Chopin being so tortured with having had to do it the first time around that he didn't want to touch it again to try to make something else out of it.