well it's an internet forum isn't it, lots of people don't like being called a cnut or whatever but Niall has decided that in the main it's ok, so to use this forum you abide by those rules. If you are overly sensitive you've got the choice to not use the forums.
If it was decided on to proceed with the 3rd tier then niall or the mods saying 'and we don't want to get pms about why it's unfair you haven't been allowed in if we do you'll get banned' would be quite clear as a rule in using the forum. if you didn't like it you could just not use the forum. it's not a democracy and it's not real life, if your banned it's not the end of the world and the mods don't ave to explain all their actions to everyone.
And yep it's like the newbie system just a 3rd tier one with fewer members, the main forums would still be the main forums being sensibly modded and so on, but posters who while too good for the newbies because they raise valid points but who also use the forum for spam and posting shit wouldn't be invited to the 'elite' forum, as Davo said traffic would probably be very slow, this would be the main forum still and users who participated in the 'elite forum would still be posting here because here is where the majority of posters would be posting.