HD8200 Lens Throw
The Optoma's 1.5:1 zoom lens will allow you to place the projector as close as 10.9 feet from a 100 inch screen (measured from the front of the lens), or as far back as 16.6 feet. This range is fine for ceiling mounting. Those with larger screens, relative to room depth, should have no trouble rear shelf mounting. Those with deeper rooms and smaller screens probably will not be able to shelf mount. For example, if you go with a 110" screen size, it will work shelf mounting, if your room is no more than about 21 feet deep: 16.6 feet x 1.1 (for the larger screen size), + 19 inches of depth puts the back of the projector about 10 inches from your back wall (assuming your screen surface is two inches off the front wall.
HD8200 Lens Shift
I've spoken about the HD8200's lens shift earlier. Here are the numbers for the working range. The HD8200 has very limited horizontal lens shift, which is fairly typical. It's shift is measured in inches, not feet, good if you need to mount the projector slightly off of the center point of your screen horizontally. Assuming you don't use any horizontal offset, then for a 100 inch diagonal screen, the projector can be mounted as low (measured from the center of the lens), as 17 inches below the bottom of the screen surface). The more horizontal shift you use, the more it limits the vertical movement (and vice versa).
The "problem" with the HD8200 is that it's lens shift is not balanced. While there's a lot of lens shift available to allow the projector to be placed well below the screen bottom, the opposite is NOT true.
As it turns out, with the projector in the normal "right-side up" position used for shelf mounting, the bottom of the image can only be placed slightly below the center of the lens. As such, you cannot shelf mount the projector any higher than a few inches above the bottom of the screen.
And since most folks will have the bottom of their screen 24 - 44 inches above the floor, the projector cannot be placed high enough so that it is above eye level, or for that matter, much above waist level. This means that, yes, you can put the HD8200 on a shelf, but you'll be walking through the projected image if you pass in front of the projector.
HD8200 Anamorphic Lens
Yes, the HD8200 supports an anamorphic lens and motorized åsled. Having the two 12 volt triggers should be helpful, in terms of controlling the sled.