I would recommend against an impact drill of any sort on anything that has to do with the word "optics". You'll take an excellent chance at stripping your threads out and possibly voiding your warranty, maybe even causing internal damage, who knows. Optics companies can be funny about things of that nature done intentionally.
+1 on the blue Loc-Tite. I use it on anything I have that I need to keep from working loose. I would use the blue loc-tite on the threads, then hand tight only on it.
Some plates have anti-twist devices built into the plates to keep the optic from spinning on the plate, helps to keep the screw from coming loose. They are little tabs that pop up and keep the base of the optic in place.