The first one is perk related. I took the "Friend if the Night" perk and it seem to work randomly. It actually sometimes makes the screen darker to the point to where my pip-boy light does not help. It will flicker off and on and sometimes it will stay dark, I'll reload the save and it will be fine.

The second one is related to "Rex the mechanical dog". I told him to stay inside the Kings building because he was getting in my way in the sewers and getting killed. I walked him all the back and gave him the "wait here" command. I finally made my way back to the sewers after about 1 hour of exploring. I was half way through and then I opened a door (one that forces a loading screen) and then there he was barking right next to me. I had to walk him back for a second time. He has since not returned, but I don't know for sure for how long.