I thought Larian already confirmed fully voiced main characters?
Regarding cinematics... right now they are just... yeah... but like it was pointed out by the guy that made the cinematics review video (I'm ashamed that I don't remember his name) the whole presentation does make sense for the orgin characters and them being voiced since you as a player know next to nothing about them and seeing their reaction actually gives you some insight in the character you are playing. Now put the promise ontop that 'the custom characters' won't be a worse experience than the origin ones' - and I see Larian have already made their bed or they will give critics just ammo to complain.
The split in Tav's voice and barks can only make sense to a user who read our conversation - if you see it without explanation in the character creation you would be at the least confused, but more likely complaining about it being a bug

I have to admit I don't like the postion Larian put themselves into by wasting the resources on orgin characters. Are more traditional approach to them being just NPCs that might step into conversations instead of having to have the full dialog recorded would have left a lot more resources for several voice sets that in my opinion would make a lot more sense when using cinematics. Coming from the old RPGs myself I don't mind the unvoiced mains up until you put them into cinematics - those simply don't work as they are now. So for me its either properly voiced or no cinematics. The way they are now (and they were in DAO) they just kill any moment they were building up to.