Graphics admins and Graal Police can both accept uploads, i'm not sure about scripters and level designers. The bodies and heads just need to have a transparent background and not be rude. Check the information kiosks for admins. For your concern about the ugly heads, the people who own the site upload them, or even site admins, someone could be just stuffing around. It is only effecting their site from getting less views so I would not worry about it to much.