That should be a good time, u can also walk around the stadium area, shops, restaurants, bars etc. But we usually tailgate then head in 45 mins before kickoff. But I would say 3:30 should be fine
If its anything like AZ, they throw both parties out involved in an altercation... so if u are getting harassed, dont say anything back or do anything so u can stay and watch the game. Speaking from personal experience, albeit at a sea vs az game!
I will be there, wife works for University of Phoenix. So she gets deals for us every year.
I laughed reading a post regarding going to the Eagles game, becaus its what I do at the pink taco stadium! Really wish they would've gotten that sponser! Anyhow I usually make friends with the cards fans...