I kinda feel the same way. That autocombo + corner pressure kills Yukiko quite quickly even if you have good defense. She just doesn't have a good answer (or reversal, I guess) to her aerial blind spot.
Btw, I just picked up the game early this month (after not playing FGs seriously since Tekken 3 and some SF4 just to learn the input commands) and for some reason, I kept going back to Yukiko even after reading around that she isn't newbie-friendly and isn't that good anymore. But what the heck, I like her gameplay design and even if I know playing her on pad isn't the best idea, I'm willing to stick with her.
Having said that, I've yet to learn all her mixups/pressure strings and I have trouble finding them. I know her BnBs and super finishers and can more or less zone with her now but I realize that it won't get me far if the opponent knows how to defend and turtle.
So, what are her mixups? Is the old P4A guide in the archives still applicable to this version?