There are 2 body control modules, a front [fem][under drivers side dash] and a rear [rem][right rear quarter trim behind jack tools] The rear is subject to water intrusion if the quarter trim windows are left open in the rain..It sounds like most of your problems are related to the rear unit. Let me know if you need more help, you can try drying out this module if its a water concern, if it smells burnt, it probably won't work and will need to be replaced.
It's really necessary to have a expensive computer scan tool to diagnose these problems, all the pinpoint tests are wrote that way. Here is a list of what each module controls.
Principles of Operation
The Windstar's electronic functions are divided into zones. The front electronic module (FEM) controls the front portion of the vehicle and the rear electronic module (REM) controls the rear portion of the vehicle. These systems rely heavily on the standard corporate protocol (SCP) communication network in order to transmit and receive signals.
The FEM controls the following systems:
Inspection and Verification
NOTE: Note: Upon installation of a new rear electronic module (REM), the module must be reconfigured. Refer to Section 418-01.
The REM controls the following systems: