you need a minimum of 10' 4" between the lens and the screen for 92". being that the hd65 is 7.4" long, plus at least 1.5" for cables, the lens will be about 9" from the wall if you placed the projector right up against it. if your room is exactly 11', then even with the screen painted on the wall it wont quite make 92".
also, if you plan on using a shelf up high it wont work very well sitting upright. since there in no lens shift with the hd65 you would have to mount it upside down somehow to the shelf for it to work properly.