I did this last summer with my college ID and it was great! The person at the ticket booth knew all about it and there was no issues on there end. I however I problems. If you are staying onsite, you CAN NOT pay with your room key. It seems like nearly everyplace at Universal that I have been to does, but when I tried to get the tickets I was turned down. Thankfully the room was just a short boat trip away and the tickets were still there when I got back.
They are strict on the 2 per ID thing. They will take your ID and input all the data from it into their system so you can't try and come back later in the day and get another 2 tickets for a discounted price.
Overall, the show was AMAZING and I can't wait to go back!