Do you use f,f+1+2~b+3+4 frequently? Your opponent can do NOTHING to Yoshi, unlike in previous Tekkens where some jabs coud hit. Now Yoshi is totally safe... and guess what! Sometimes, if your opponent attacks just after f,f+1+2, Yoshi evades his move with b+3+4... and ends face forward him! I think it's not the matter of cancel/justframe... I think it's more a game bug or something. (or maybe I'm wrong, who knows) But it's extremely useful. Your opponent opened for d/f+2 off-axis juggles. Yeah!
Out of f+3+4~b you not only can do BT moves depending on timing... you can also recover BT. I do it by pressing and holding U/F and releasing it just before Yoshi wants to escape from a window. (or: just before he stops shouting "Moooo!" :D). It can lead to nice show-off game, e.g.
f+3+4~b,U/F,N, D/B+2,2,2... (spinning backwards)
or my beloved BT jumping hopkick (don't need to release U/F)
f,f+3+4, 1+2 is useful after ending juggles if your opponent quickrolls and don't press active guard. For example:
u/f+3, f+1, b+1,1,(1),1, b+1, f+3 standard juggle into f,f+3+4,1+2 - nice thing! The f,f+3+4 will hit and by 1+2 Yoshi will escape awaaaaay (if opponent will try to run at you, hopkick him...)
If opponent presses active guard, no problem, after techroll he's in such an alingment that Yoshi will go past him... again awaaaaaay.
f,f+3+4,1+2 is also useful if ou know that e.g. after FC,d/f+3 your opponent stands up (or uses any kicks). If he'll stand straight way, shark attack catches him for massive damage.
Post your strategies, too!