I can't confirm or deny your second point, but I was testing out the conversation at the police station with and without the social aug and I definitely had different response to the same tactic in different attempts. Some may have just been because I had used a different tactic in the first choice, but the same one in the second, while others I definitely picked the same options.
From what I can remember, there were at least a couple different lines that all more or less said the same thing, but with different inflections. One was more defiant while another was more sad and beaten.
After 15 hours I'm just leaving Detroit. Having a lot of fun so far. I've mostly upgraded my hacking skills with a few points in extra battery cells and the ability to punch through walls. Favourite part so far has to be sneaking through the last story mission in Detroit. "Ghost"ing that section was a lot of fun, although I dunno if it's really ghosting if I stopped to talk to the two non-hostile guys there.