We currently do not have a device template at the moment to support a proximity reader, but one can be made using the available tools.
As for determining if people are already inside, you would need to have some sort of way to generate the appropriate event of "Presence Detected" for a given user. Again, you would need to develop a driver using the available tools, and then you could construct an event response around it to lock/unlock the door.
-Thom