I hope there's no problem about reviving old topics but.
I think this is awesome. I can tell you that this is a thing and for example, Don't starve has it.
The characters say something depending of the action, also when examining something ( tbh I love doing that lol ), or when they're going to be attacked by hounds or when they're attacking the monsters they say small lines like 'I'll smack you' but this obviously depends of the character. Of course, it doesn't have to be voiced so it brings zombies, it can be as you said, a thought. And also, the 'Q' line should have other options maybe?