Ok first off Reddragon lol @ your sig.. the resolution size fucked or summat?
Are the numerous stories on the net about xbox being full of 12 year old true? (by the way ,unlike what most people think ,I would not consider this a plus)
Yes unfortunatly the majority of the xboxlive is full of kids, especially cock of doodey modern warfare, however the more 'grown up games' like BattlefieldBC2, Forza, Grid (our kinda games) are populated by the less retards of society.
Is the hosting any good?
Yes, BFBC2 is dedicated servers from what i can see, and not had problems with them at all apart from the blip on the first weekend, but now not had a single problem
MW2 is player hosted, but if that player leaves or has shit connection speed, the host migrates to another player instead of closing down.
Overall ive never had problems with hosting on the 360, pretty much all online games work fine for me, apart from AvP which ahs some serious issues.
Are FPS's any good on the Xbox controller
It will take practice, im the same as you, have played FPS games on PC for years, and switching over to console and pad is not easy at all, but eventually you will click and get it, i find turning the sensitivity down to pretty much 0 helps a hell of a lot, but thats just me. I wont lie, its not easy, and i dont like it (god bring us the day a usb mouse and keyboard is released for the 360)
Is it worth it to buy a gold account for internet access?
Overall: Yes. Dont pay microsoft prices though, talk to Lazarus he knows some cheap places to buy access from. Having a Gold acount is only really viable if you intend to play games online, if not then you can probably get away with a silver account. But again a gold account does unlock stuff on the marketplace.