slow time won't break CC if you force pull the other mobs away from the CCed one.
i didn't have anything saved up for Nadia either. i just gave her my old gear when i found better pieces to wear.
as far as tanking goes, it's a bit different in each game, at least the ones that i've played. leveling as a tank in this game is much easier due to the companions, though holding agro when you're in a party can be difficult at times (for a guardian anyways, shadow had less problems holding aoe threat due to slow time being spammable). this is also the first game i've played where a tank class has stealth. surprisingly, it works. had to get used to it at first, lol.