Can I make CIH in the following way ?.

I want to go CIH, but have several reservations:

1. I want to use all the resolution of the panel, in both 16:9 and 2.35:1.

2. I don't want to use an anamorphic lens, because I don't have the money to buy one that won't degrade the picture.

3. My projector will probably have no lens shift, and minimal zoom range.

The above requirements possibly rob me of any way of doing CIH, except maybe the following way:

What if I were to mount the projector on a ceiling track ?. This way, if I want to watch 16:9 material, I push the pj forward on the track (to make a smaller picture), and when I'll want to watch 2.35:1, I'll push it backwards on the track. Actually, I can make the forward end of the track at a distance perfect for 16:9, and the backward end of the track perfect for 2.35:1, this way I will be able to easily and accurately switch between modes, because each mode will be the end of the track (this way I won't have to struggle with finding the exact right distance for each mode, everytime I switch).

Is it theoretically and practiclly possible ?, if so, what I are the downsides for this scheme ?.

Thanks.

You're right, what I wanted to say in requirement #1, is actually that I want to use the entire *horizontal* resolution, in each mode.

Is there a projector that will not be compatible with the scheme I outlined above ?.

I will have to change focus everytime I switch between modes. Do you think this constant play with the focus mechanism could shortly lead to failure of the mechanism ?, i.e is the focus mechanism usually robust enough to endure such "torture" ?.

Another question:
When switching beween modes, will the center point of the 16:9 and 2.35:1 images, will overlap on the same point on the screen ?. If straight light leaving the projector lens, does not hit directly at the center of the screen, I can't see this happening (and I think many projectors shoot at an angle). Is this indeed a problem ?.