This is why I prefer to look at this with numbers. With a 50-55% chance of a FG, I would love to know the relative risk of the choices between a 51 yard FD (kneeling), a 56 yard FG (run wide left) or a play action pass.
I think you have done a very good job of explicating the risk of a pass here. I think its easy to figure out a FG here is no sure thing and a 5 yard longer FG is a worse option. But this is only the risk side of the equation. We don't know the upside of a completion, the likelihood of it being made multiplied by its effect on the game situation.