Parking is one of the points i'm still waiting to have hammered out, but the timeslot, day, and room are locked/reserved for us. Turns out the coordinator I had been communicating with this whole time will not be here by monday next week, so everything is shifting to a different coordinator that I have to re-explain everything to. Personally, based on how up in the air the number of people coming can be I'd say we probably won't use passes. There is a 4 story parking structure attached to the building though and it will by no means be full at 12pm on a Saturday. Maybe getting close by 6pm but never that early. As for price of 5 hours in the parking structure vs passes, I'm going to be discussing that. We also were much better off in the timeslot we chose, as 6pm on usually means wedding receptions + DJ + right above the room on saturdays.
I'll keep posting any developments as they happen.