i have no clue for the drillshine, but for the uair, its better to DI behind fox when he does his uair, however, if ur really high percentage and that even with DI ur character will die, to SDI it, u smash it up for the first hit, so ur out of the range and the 2nd hit wont touch u. this only works if his feet are on u, if his body is pretty much in u, ur SDI wont get u up and away far enough to avoid the 2nd hit.
edit: some tips for trying to get out of drillshining could be:
1. if his drill is hitting u, i think u can crouch cancel and try to dsmash it, i never actually tried this technique, but it could work, otherwise u could just try and hold ur shield, or crouch cancel to grab, it only works if he misses his l-cancel.
2. if his drill is hitting ur shield, ur best option is to just roll away, if hes not very good at l-cancelling, u can attempt to shield grab, but its somewhat risky, especially for peach.