I came here to ask this same question. I've played every DA and ME and a host of CRPGs over the last 30 years, and somehow I'm completely lost on half the mechanics in this game. I don't know if its lack of a manual, incomplete tutorial, or if I'm just getting old.
I still don't understand what focus is.
The inquisition perk that mentions focus also says that it opens tier 2 abilities. What is a tier 2 ability? Does tier 2 mean the little diamonds beside the big diamonds? Because I noticed I've been unlocking those but none of my party members do when I auto level them, so I wonder if they're doing anything for me at all.
So, is focus a higher level thing? I'm at level 9 right now. And when do specializations come into play?