They aim to have class related quests. They plan on having more classes than pregens. Ergo there will be some quests that no pregen can do. The same could well be true fore races and backgrounds. They haven't said anything to suggest they will use DoS2 tags instead of backgrounds, and mechanically it's easy to convert one system to the other - instead of choosing two tags you choose one background, the background has a bigger impact.
As for "fully voiced" the answer is in the AMA - there will be a several full voice sets just for custom characters.
I'll add for custome characters there is the unique element that the game appears to assume you are either Baldurian, Underdark native, or whatever catogory Githyanki fall into depending on your race, which I don't think for the most part is true with Companions.
For healing with Hit Dice Swen confirmed that it's in.
> How are you planning to compensate for removing most reactions and short rests? Reactions are not removed, they are available as actions, passives, or toggles. Short rest is not removed completely, you can still use the Hit Dice heal from the end of the short rest.
Did they indicate if weapons and armour are going to be modeled like they are in 5e or or if they are going to follow a model similar to DOS2 or Diablo where you are always on the lookout for weapons and armour with slightly better values? The latter always felt weird and arbitrary to me.
Amusingly, you stand relatively alone in this regard. The idea that BG3 would have Original Sin style itemization was one of the biggest concerns I was seeing with regard to Larian working the project. There were quite a few sighs of relief over this tidbit.
That's okay when it's a kill-the-monster-take-the-loot Diablo style video game. But this game is long. It will have lots of varied challenges along the way. It's not expected to be played dozens of times - most people play this kind of game only once.