The third one is answered already during application process, but extended on anyways in ability rules (as of this post). The general guideline is incapacitated in some way, a huge cost for the amount of power used all at once. The most common one is fatigue state throughout the rest of the thread (as you personally saw on Yuri's Ragnarok). To my knowledge, the only character that can "recover" from such a final move is my character Kai, and he's in fatigue state for 8 posts and requires 2 reiatsu suppressors just to keep his shit in check and can't hide at all, and even after that recovery he ain't fighting for very long or else it's mostly physical.
The first can get interesting as there are some purely equipment based characters. Zackary just being the most recent one and has costs of his own (his powers are his equipment). So, care to elaborate on what you mean for this one? And for the second one, since I don't know what you mean on that one at all.
The fourth one we'll talk over. As it is, generally speaking, Hollows have the most henchman, followed by the Serion (easy to replenish numbers/sheer numbers), and then the Coalition and Gotei 13 are tied (both needing to recruit and then train, with the Coalition home base having some defenses and a police force for reinforcements). The others literally just have their respective "officers" in charge as their members with no henchman etc., but are currently offline until/unless they get some actual members beyond just two or three peeps. Again, we'll talk about it, but maybe elaborate a little bit more on this one too.
The last one can also get a bit interesting. It is touched on somewhat in the fighting style section of creation help, so anything more would probably be added on with that. Not sure if you've checked that out, but please do and give some feedback on what may be added onto or if you think this should be it's own thread for the Creation Help section.
For the record, while it hasn't been talked about extensively, but we are thinking about a facelift and advertising a bunch. We've even cleaned out all of the unused apps. Alas, RL is getting somewhat in the way of that.