This isn't an answer to any of your questions or a suggestion of any kind. Just an observation. You have by your own admission a LOT of lightweight parts going into that rifle, especially into the rear end. What is the contour of the barrel? A .936 gas journal might suggest the barrel is heading toward a heavy bull barrel. A bull barrel out front, especially at 22" long, and all those lightweight parts in the rear, could make for one very nose heavy rifle. You mentioned a suppressor. That will add even more nose weight.