So basicly you mean that Blizz is not allowed to read out their own game client's data to check what kind of addons you are using in their game?
As i said i am totally clueless about this i have read a lot of things so far like they can not scan your Windows processes or scan outside of the memory area of WoW. Anyway it would be strange to me as the developer of my own game i would not be allowed to check for game parameters (addons, computer specifications etc.) but i am not a lawyer.
All in all i wanted to point out the simple fact that having PQInterface loaded should be a sign of cheating if they are allowed to read your ingame addons what does not have anything to do about the way PQIterface works.
Holding a gun (PQI) even though it is not loaded (PQR is not loaded) in the post office / bank would have its consequences. (I could nto come up with a better example from irl sorry
P.S. I think we should continue this in PMs because i don't want to hijack the thread or frighten anyone.