nope, never occurs to me, though summons happens pretty rarely though.
Nope... my setting stays each time i set them...
You should be able to use hairworks and other nvidia features there if you're on 1080p with your specs. On other resolution, may wanna turn down a little. Im on the same setup as yours, except its 1080ti, if i can maintain decent performance on 1440p, the 1080 should be able to do so on 1080p with a breeze.