Hey Vox.
I have one of the Magic Force 68's and notice the stutter as well you pretty much have to use 20 c/s polling for games sadly. I'm guessing it has something to do with how the board is trying to force that faster polling and the game is in turn seeing it as multiple keypresses or something similar. When I was using mine I just left it at 20, you don't really notice the difference inside or outside of gaming.
As for silencing, other than opening the switches and changing the stem or going to a one piece stem, etc... Your best option really is the orings sadly. Most other ways to silence or quite them down involve desoldering the switches.
Hope that helps!