If you go in the morning, go early. The staff takes their lunch break from 12 to 1pm, and unless you enjoy staring at walls, there ain't much entertainment during the wait. Bring a book or Chess set.
Copyshop and passport photos downstairs in the mall at regular prices (2 Baht per copy). You can take a queue number and then go make the copies, there's usually enough time...
Opens at 08:30, queue begins at around 06:45. People are kind enough to leave bags in queue and you could sit. People will jump around you when it opens, so be careful.