Yoshimitsu has the following just frames:
i.


:

(Instant Manji Carve Fist)
or FC

:

(Manji Carve Fist)
ii.

:

(Parting Thrust)
iii.


:

:

:

:

(Stone Backhands)
iv.


:

:

:

:

(Stone Fist)
v. FC


:

:

:

:

(Spinning Low Kick)
vi. SDF

:

(Acrobatic Bliss)
vii.



:

etc (Manji Blood Dance:Bliss Stance)
viii. MED

on aGI

:

(Extermination:Bliss Stance)
i. It's essential that you are start pressing 2 at the exact same time as A. You can hold down when you slide to B, but it must be in 1-2 frames. Full crouch is just holding 2 in FC and sliding a:B the same way. 2a:B+K is confirmed to work so you do not have to bind another slide.
ii. The slide is similar in iMCF but can be executed slower. Just add a K to your B for B+K. Most Yoshi players bind B+K to do this attack as it makes it simpler.
iii.
http://soundcloud.com/mr-kloux/yoshi-4a-jf
When you do this correctly it stuns them (or launches them if they're mid air). Yoshi has a chance to get dizzy so there is luck involved in taking advantage of a stun or relaunch.
iv. I will get around to doing a soundcloud for the timing of this.
v. I'm actually not sure what the timing is at all yet, I'll update this soon.
vi. Press the second K right before you land. Very strict. You can get the standard recovery if you are in the ballpark.
vii. You can mash this one pretty consistently so I am unaware of the timing. I believe it is right before you start your falling animation.
viii. You need to JF time both Ks. The first K is right as Yoshi's head his the ground and the second is just like the timing of SDF K:K, right when you hit the ground.
Any frustrations about his many JF attacks can be voiced here. Help is always welcome as these attacks frustrate many players.