Can I have two teams register to me and in the same ladder with some of the same players? The reason I ask is because I have a lot of clan members and trying to rotate so all can get a chance to play is a pain.
no,
you can not be registered in the same ladder twice. It will not let you. The only way to do it is to make a second account which will earn you a vacation. If a player were allowed to play on different teams in the same ladder, it would end up creating ringers.
Plenty of clans have more than one team in a ladder, it just has to have a different founder and players in it.