If the exp-difference was removed, the only reason to go bmode would be to pk - or to have a kingdom war, at least for now. I think this would work fine.
As for the ac/wc thing, I don't know how easy (or rather hard) it would be to implement/change. In theory, it should be possible not to be able to hit someone at all (thick platemail against meager dagger), but then again, what's this theory worth in GK, where a bow can fire faster than any smg
