In a few weeks this place is probably going to be flooded with people, and we're going to need a bit more organization here, so I've got a few suggestions.
1.) You are probably going to need mods at some point, or split the forums into sections for current testers (read-only for newcomers) and prospective testers (for questions and non-testing discussion)
2.) Invite requests should be moved into a single thread, and a moderator should try and keep the requests out of build release notes or bug threads.
3.) Perhaps some kind of differentiation between current testers and uninvited testers. We could have visibly discernible user groups (like the tag on the left that shows "Brave Tester") so that invite threads can be sifted for people that are not yet invited, or so that threads can be sorted for relevant tester content.