Am I playing too scared?

[TheScientist]

I actually love this line. You've got two players probably drawing close to dead. Let the idiots hang themselves with AK, JJ, A4, 66, or maybe some other hand they might fold if you played your hand aggressively.

And I've seen stranger things than someone leading with AQ here, it's not unheard of. (especially after it's 3 barreled, against a sane player the chance of a Q goes up significantly IMO).
Thus, I would probably not raise the river. Against an aggro/showdownish player I might go for a raise if the board was safe on the river.