Some GvG, rated/unrated ?s

1: What's the deal with issuing an unrated challenge? Do it not effect your rating? Just making sure

2: Why can you only issue an unrated challenge to a specific guild?

3: Is it possible to select a random opponent for unrated matches.

I need to know in the next 5 minutes. Please answer quickly.

Thanks.

Um..............Hello? Anyone there? I really don't want to bump this, but I need these questions answered.