The Mitsubishi site has the min/max info I think you're looking for.http://www.mitsubishi-hometheater.co...hi_HD1000U.pdf
At the bottom of the pdf it shows what screen size you can get -- about 101", as you estimated.
You can buy a zoom from Mitsu but it's pretty expensive. It would be in your best interest ($$$) to just find a way to put the PJ a bit farther back in your room if you can -- maybe by adding another support, or by using the adapter hardware that's been mentioned when you don't have a stud to attach it to.
Sorry - No knowledge of "specific knowledge" on DLP vs LCD (still a newbie), but I do know that I specifically didn't want to deal with the SDE that LCD supposedly can give more readily.