myklia, I'm not sure if you can change your Craftster username.. I looked in my profile settings but didn't see a way. Perhaps pm a mod to ask?
As for Ravelry, it interfaces with flickr accounts only, so if you want pictures you'll need to set up an account there.
It took about a week and a half to get my invite, and when I signed up there were about 4000+ people ahead of me. It was a bit tortuous waiting all that time, but it's totally worth it.
I've spent all day over there today. *lol*