Andrew
Your prototype design has a lot of merit! Here are some preliminary comments which I hope will help you.
Lobby: With a complex of about 2000 seats, the lobby needs to be way better organized to avoid confusion, congestion, and allow for adequate circulation and holding areas for patrons. I would recommend at least 8 ticket stations, and would prefer a "flow-through" arrangement (like supermarket check out counters) to speed up ticket sales and improve flow. Yes, there has to be a cash room connected to the box office. The arrangement of concession areas needs to be improved. The main stand is at a dead end of the lobby, so people can buy their tickets and go directly to the cinemas without ever passing the concession stand. This is a no-no. You have to force everyone past the stands. At the same time, there has to be clear areas to line up for food, while still allowing for entry and egress of patrons. You can't rely on the exits at each end of the lobby, because people are reluctant to go out in a direction different from where they came in. Main exit areas should go back through the main lobby, but segregated in some way so that they don't cross the lines of people coming in.
Auditoriums:
Exiting from the auditoriums which are sandwiched between other screens will be difficult, without compromising screen sizes. We have often taken the exits down under the screens, but you can't raise the screens too high. A simple solution is to raise the floor at the front of the auditoriums about 3 feet by ramping up from the lobby. This will allow you to exit down about 4 or 5 steps, go under the screen and exit at ground level. This is assuming you want stadiums. The objective is to get wall-to-wall screens and good sightline geometry. We have computer programs to generate our sightlines.
Hope this helps.