Startup frames :
jab 2 frames
nair 4 frames
dtilt, ftilt, utilt, dsmash 8 frames
bair 9 frames
fair, all grabs 14 frames
usmash might be 14 or 16, idk. But yeah slow af.
jump squat 5 frames (not super sure on that one)
Shield advantage :
nair has a landing hitbox so as long as it hits and you L canceled properly it's -2 on shield
everything else is at least -8 afaik, but you can make it safe with spacing instead.
Smashes are not safe on shield even if charged and/or well spaced.
Ledge stuff :
The distance between you and the ledge determines the duration of the pull up animation. Typically it's between 2 and 4 frames.
If ledgehogged, you will go through a 50 frames long animation. You can land as soon as frame 27 during that animation, but it makes you go through a 20 frames long landing animation unless you ledge cancel.
I believe you can hang on the tether for 30 frames ? Not sure at all.
The rest never felt relevant enough for me to learn it, but have it your way mate. Shield release, rolls and spot dodges are all important to know as well, but they're universal now so do yourself a favor and learn them, it'll be useful regardless of which character you play as or against in PM.