Two drop down front feet are located at the far left and right front of the projector. Each has a single button (mounted to the side) to drop/lock the feet).
Moving to the top of the Optoma HD7100, up behind the lens are two recessed slides one for adjusting the zoom and the other for the focus.
Looking at the HD7100 from the back, to the left of the recessed area for focus and zoom, is a wheel that adjusts vertical lens shift. The HD7100 allows you to place the projector - the center of its lens actually) slightly below the bottom of the screen surface to any position up to slightly above the top of the screen surface. Here's a basic spec for the "outer range", you can use it and figure out your own placement.
If you have a 100" diagonal screen, the center of lens can be as low as 4.1" below the bottom, or above the top of the screen surface. (If you screen is 10% larger - say 110" diagonal, then you would have 4.1" * 110% = about 4.5" instead.
But, back to the controls. There is also horizontal lens shift which simplifies left/right mounting (especially in light of an off center mounted lens).
Behind all the lens related controls, is the main control panel shown here. It is well laid out, with the standard four arrow keys and a center Enter function, closest to the lens controls.
Straight back is the power off/on, first is a small indicator light that alerts you to a high temperature issue. Then comes a large button that lights up bright blue when the projector is off, and blinks when powering up/down. Optoma apparently learned well from the H78DC3 and H79, both of which also had bright blue power indicator lights that stayed on, when the projector was on. (In all fairness the light was on the side, but many people covered itwith tape, because it was bright). So this time, once the projector is projecting an image, the light stays off until you power down. A good move on Optoma's part!