Cool. I think it'll take some getting used to seeing people with avatars who didn't have them before. I'm not sure whether to have one or not now. I think it's a wise idea to limit then to Full Members too.
Sweet. In theory this should cut down on the number of scams when people create brand new impersonation accounts as it is difficult to impersonate an avatar without the ability to upload an avatar (as a brand new member)
Hopefully, but some people can never be helped. Theymos also didn't have an avatar before so they could still impersonate him.