Hi Thirion! Welcome!
I'm not sure what will be happening with the classes. I imagine they will probably follow the open-class system of Div1 and BD to some degree. Perhaps they'll offer incentives to select skills from a similar path?
On the music, as nice as the track you posted is, I struggle to see that fitting with Divinity's theme. We know that Kirill Pokrovsky, who made the music for Div1 and BD, is doing the music for Div2 as well. Maybe you'll just have to leave your MP3 player running with the game.
Good to see you here. Hang around and join our madness!
