I don't have a Southwind, but I can answer some of your questions.On our rig the panel maintains the chassis battery. The panel will not charge a battery (it's too small for that), it is meant to maintain a charge, to offset the 'phantom loads' such as the propane detector, engine and transmission computers, radio memory, etc. The red LED light should be on when the sun is shining, it just means there is an electrical current flowing; of course, since it is a diode, it prevents current flowing the wrong way when the sun isn't out.
The disconnect switches will not affect the solar panel, they also will not turn off the phantom loads.
Hope this helps a little,
'97 Bounder, 32H, Chevy 454; ipd, Bilsteins, Air Lift, Banks, Hendersons, Solar.