way to call everybody a pretentious elitist and then deride everybody who does uthrow uair (read: every fox ever) in a pretentious manner. real classy, bro!
anyway, against an opponent who SDI's the uair to the side, you can aim the uair such that it turns into a 50/50 mixup - don't go straight up at 'em, go at them at an angle. be clever about how you jump up there for the uair.
a lot of people have a pattern to how they SDI the uair, too. in a moneymatch with eggz's marth a while back he got visibly frustrated and exclaimed "why can't I SDI your uthrow uair? this is bull****, i'm usually really good at it." I was like, "no, you're definitely hitting the SDI, but you SDI to the right (might've been to the left, I don't quite remember) every time, so i just lean to the right as i get up there."
works against puff too. :D
dthrow is decent, but the mixup has too many options for me to like doing it more than once in a while. DI away + no tech is irritating to punish, for example.
sorry, I'm not sure on the %s you can CC puff's fair/bair. I don't think bair goes up nearly that high though. I'd estimate 70-80% before it knocks you down. you could test it if you're at home by resetting a 2nd controller so it's always crouching, then go into a match and experiment yourself.