A:Answer Yes the mount tilts. The mount has a full range of motion: tilting up, down, left, and right...as well as pulling it out from the wall and pushing it back. The mount comes with several different mounting brackets including VESA mounting hardware and pretty much all new Samsung models adhere to VESA standards. So long as the mount is properly installed, it should support the weight of either of those TV models. The mount is rated to support 125 lbs; the QN75Q70R weighs 79 lbs without the stand and the QN82Q70 weighs 94 lbs without the stand. However, I used this mount for a QN75Q80R that weighs 82 lbs without the stand and it seemed a bit precarious while making angle adjustments. Because of this, I downsized to the QN65Q80R that weighs 56 lbs without stand and it works wonderfully.
TLDR: Yes, it tilts. Yes it will fit either of those TV models. However, based on my own experience with this mount, I would recommend a more robust mount for those models despite the mount's weight rating.