For a 100" screen, your projector could be mounted anywere from 8' 4" to 10' 11". If you put it at 14', it looks like you'd be in the range of a 129" screen (assuming 1.78:1)
As for the drop, that pj doesn't have much vertical shift. There won't be a lot you can do to hide it if you are set on a 100" screen.
Nothing in this world will tick you off more than seeing a vegetarian eating pudding.