My UN65F8000 is mounted similar to what you want to do. In my case I already had the (expensive) furniture from my prior TV, a 65" Mitsubishi RPTV. CRT rear projections were very deep, but I wanted to use the same furniture but mount the F8000 near the front. I have only about an inch on each side, an inch and a half on top, and about two inches or so below the TV. The main reason for the 2 inches above is to clear the pop-up camera on the TV. I have no heat issues at all, however I do have a LOT of open space behind the TV (see pictures). The black piece below the screen it a cloth covered quick 'n dirty filler. Eventually I intend to make a nicer piece with some shelves, and move my 50 pound center channel down from the top of the world.
Note: The mount picture shows the stand attached to the TV. The stand is
not normally attached.