While I agree GM has final say even when they do just use houserules in mission games, it'll be nice to have answers to some of the more frequently asked questions by players to GMs. Really a lot of these issues have less to do with players trying to pull a fast one on the GM and more to do with poor writing and rules design.
The ones I see are how mystic adepts work (due to accepting the FAQ), how assensing and mundane stealth interact, can one act normally after being hit by a control X spell but before given orders, how the swap echo works, how heightened concentration works, and how critical strike and unarmed skill using weapons interact.
Also how is the FAQ coming along?