Mitsubishi HC3000 Mounting Issue

Without fully researching ahead of time, I went ahead and bought the Mitsubishi HC 3000 and a 92" screen, mounted the screen and put the projector on a box figuring I can use it like this until I get to mounting it on the ceiling.

Well, after looking at the mounting calculator on the Mitsubishi site, I have no shot at ceiling mounting, do I? Here are the stats:

Basement ceiling is 91" high
Screen is mounted where the wall meets the ceiling (top of screen is about 85" high).
Projector is about 11 feet back, but there is plenty of room both ways. For 92", however, this seems to be about where it belongs.

I don't want to move the screen down as the middle of the wall will not lok good.

If I leave it on a table on the floor, is there a way to secure it so that bumping the table doesn't screw with the alignment?

Any suggestions for a decorative table that the wife may not object to?

Oh, and with the seating about 17-18' back, rear projection just isn't big enough.

Thanks!!!

Well, its up! About 12 feet back on the 91" ceiling (dropped about 4 inches due to the mount). Screen is 92" diag mounted where the wall meets the ceiling. Seating about 4-5 feet behind the projector.

As Jack mentioned, not perfectly square, used a bit of keystoning and it's probalby 98% in terms of positioning on the screen. If you don't know it's not perfect you wouldn't notice. Beats having it on the floor.

The HD box comes today so anxious to see what this can really produce. So far I have just been using a regular video-in RCA cable. OK for SD but, not surprisingly, won't blow anyone away.

3 questions:

1. This is my 1st projector. When aspect is set to auto, will the ratio automatically switch from 16:9 to 4:3 based on program source (as my Sony SXRD does)? I will be using an HDMI cable.

2. I am hooking up an Xbox 360 and a separate DVD player (non HD for now). With only 1 component input and 1 HDMI input, is my only solution getting a component switching box for the Xbox and DVD player? Seems like meager inputs for what was a $3K unit.

3. WHat about cleaning the lens. I already notice small dust particles in the light stream that are on the lens. Am I being neurotic? WHat is the safest way to clean and how often - in other words, will this affect the projected image?

Thanks to all for the help!!