I agree character development does play a big role but I think you can atleast help by personalizing your character so the writers have atleast an idea. "Cocky, arrogant heel" isnt really a gimmick, its a personality. How far can you develop a character going just by that (obviously roleplays help) but having a more in-depth and orginal biography can only help the writers, it doesnt hurt.
The Character Development RP Board should play a big part, and even though it doesnt count towards your match for that week, its giving the writers as well as everyone else more details and information that can be used in angles,matches, etc...
For all the new guys who have just joined (and for those who are thinking about joining), just remember..if WWE was just Randy Orton type wrestlers, it wouldnt be very entertaining..unless you have a man crush on him or something.