Alright, after some discussion with some friends and some deciding based on centralized location, the AMC Pacific Place Theatre 11 would be close to PF Changs for quick travel to the theatre after the dinner is over. The theatre is a decent size, has both stadium and standard seating and "Loveseats" designed for 2 to snuggle in.
Here is a link to their websitePacific Place Theatre 11
They have convenient foodstuffs there, a cafe upstairs, and is rated well for comfort and customer service. There are, of course, bad reviews, mostly concerning the service, and mostly during the day.
You can find a place in there that does advertise private parties and renting out theatres for exclusive events, but as far as group discounts go, they outright say those don't exist. I've yet to find any info on how large the theatres are, but I can continue looking about.
But, for distance from dinner, this place can't be beat.
P.F. Chang's: 400 Pine St.
Pacific Place Theatre 11: 600 Pine St.