Send an email to the Fox. I'm sure they would like some constructive criticism.
That said, the Fox can be a beast when completely full. Part of that crowding is from the AA set up...it bottlenecks all of the over 21 folks to the one side, and just becomes crazy.
I love the Fox, but despise sold out shows.
Sorry you had a bum time, Jen.
(oh, and I have thoroughly enjoyed YMSB at Red Rocks, for what it's worth. I was leery of their ability to "fill the place" musically...but they do a fantastic job with it.