[Grind]

I haven't seen anything about players being able to attack opposing faction's capitals but I did read an interview that said there might be missions where hybrids are attacking the capitals.

As for faction leaders and sub factions, I haven't seen any information about that but I would assume that they have some kind of hero type guy that gives you missions and stuff. I have no idea if you'd see them in battle though (that would be awesome if you did)