When I leveled my shadow, slow time still broke cc and as it was the first character I made on early access I had no idea she would be a willpower main stat comp so I hadn't been saving anything for her. The reason I made a shadow is in large part due to nostalgia for my shadowknight from EQ1. I've been tanking since 1999 so there was no need to get used to defensives. In fact, this game is decidedly less busy than that one with regard to constantly having to press "oh s&*%" buttons using a healer comp or not.
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.