Very true. Just make sure that the tank pulls aggro first, before the healer goes to CC something. Otherwise your chances of losing your healer are high.
Yes. For example Sorcerer/Sage CC is engaging combat so they have to do their job after fight starts. Like I said, Operatives and Scoundrels can stealth CC their target. Of course it's more useful when skipping trash groups you don't want to fight.
Also one of the things you have to be careful with as tank, CC'd mob will usually attack the player who CC'd them. So be ready to grab the aggro if mob goes for healer.