pretty much.

and yeah stuff like chakra would be out, ability, but no cast time.
+3 might be a bit of a limit, as stated by Velo.

as for standard attack, not to sure about whether or not that'd be allowed, as one could undermine the challenge completely with high attack classes.

items aren't really infinite - and would definitely be needed early on with this kind of approach, at least I think they would be. (+3 up anyway, +1 up wouldn't be so bad early on)

I think items would be best left as a non-specified.