When I run Bleach - Rising Stars, a RP set in the Bleach Universe, I really only stick to the common things. How many squads there are, the setting, etc. Characters and stuff are thrown out(aside from the Byakuya(sp) clan's role in squad 6. Even then, I'll not accept a character that is basically a straight port of a canon Bleach Character, with a new name. 

So, basically, sticking to the established canon isn't important to me when it comes to characters, but is when it comes to the actual universe.

Though, on Ellri's last point about 100% canon, a lot of zombie RPs get really close. xD. It's basically almost all running from point A to point B. Even mine, to an extent. xD