BEagle - are you talking about airfields without ATC? Where I fly if the guy in front has been told he's No.1 but is flying wide circuits, ATC won't be too pleased if I decide to make myself No.1.
I could of course compalin to ATC about him, and I have, in which case they may or may not change things - sometimes they just tell me I'm No. 2 and to maintain my own separation.
As for turning crosswind, I was taught not to do it below 500ft, but if you turn too early it can get a bit confussing with planes joining crosswind who will be going over the threshold at circuit height - you'll end up climbing into them.