Er, in order: No. No. Yes, swimming is fun. No, sitting doesn't hurt. I feel good right after I exercise, but when I cool down my knees start to hurt. I'd say my tolerance of pain isn't high or low. Not really. At any rate, I've been trying to become more flexible. I figured out how to do a proper squat without wrecking my knees, anyway. And a knee brace is probably going to be in my future, I just haven't needed it yet. I think.