Question about Wanted-GMs rule
Yup ... common sense prevails - it's all about consideration for other users.
If you're chasing a game for a particular character, then it's OK to mention that in the initial request, but we'd expect minimal detail - just the absolute basics to get the concept across - and any back and forth between prospective player and prospective GM around that should occur either in the relevant game thread OR rMail, ie not in the Wanted-GM post.
We definitely don't want to see a request for a game with a follow up post (once a GM has shown interest) that goes on to specify character details no matter how minimal.
As has been suggested, the rules there so that other users of the forum are not swamped with posts that are of no relevance to them (if they weren't prepared to run that game, they're definitely not interested in the minutiae of the character creation). The idea is that once someone makes contact, take it elsewhere (in game or rMail). :>