Does this mean all our mecha are vertically squashed to the same size? :0
I'm told this might be used to make a CAST. It's written by you. Plus it names CASTs specifically. AND repeatedly. According to this one at least, Cure spells work just fine.
That's what suposed to be used for making a CAST yes.
However CASTs and mechas are two diferent things. CASTs are human-sized and autonomous, mechas are massive but need pilots inside to control them. Said pilot can be a CAST.
Hm, maybe I should use one of the Evangelions as a mecha appearance? Decisions, decisions...Wait. You didn't select this yet?
Also. I'm not sure what exactly is included in "self-buff class abilities for fighting" as far as what a character's abilities transferring to the mech goes.
Self-buff means things that grant you temporary bonuses to a stat or does it include permanent benefits, like classes granting immunities to certain types of damage, fast healing, spell resistance, pounce and so on. Might also have missed the part about it but does a mecha benefits from the pilot's magic items?
Yes to all of those except magic items. However gear that increases your own stats affects the mecha as relevant, like a belt of giant strenght/gloves of dexterity increasing the mecha's own Str/Dex score, as they're the same as the pilot's.
Quite nice fluff there BTW.
Does the "mecha weapons always provoke attacks of opportunity for firing while threatened" rule mean that abilities which allow ranged attacks to not provoke do not function for such weapons?