Ah. Well that's kind of the beauty of it. You can be whatever.
On a site I used to frequent, the RPs went all crazy mad with trends (anime, vampires, ninjas, werewolfs, half-demons), so I made a fiery half-demon unicorn that throws ninja stars and changes into a vampire during a full moon. That was my protest, but I fit right in (it was annoying). So I made a non-combatant who was looking for something. Nothing in particular..just...something. Everyone thought I was lame. The point? Story-driven RP is great--it can be amazing. But an RP that involves little character development (but a lot of "I stab u with my swrd to ur head!") is really a waste of time.
Character restrictions? I'm not a fan. Player restrictions? If someone can't play nice.