So I'm at the beginning of the 3rd Act right now and I have seen some. I've also not seen the Dragonborn hireling but I wasn't sure if it was because I play a Dragonborn Sorcerer myself.
As for NPCs I've only seen three in Act 3 up to now:
One you fight against in a group that protects a ship from the cult under Baldur's Gate I think. They fought me immediately so I don't know If they have something to say.
The other is a refugee in the village in front of the city. You can talk to him but it's just a one-liner.
The third is after the first gate next to Sharess' Caress, or however it is called, trying to sell some guy some kind of Viagra-esque potion or something.
