In crayon, see my answers below next to your questions.
2000 Coachman / Ford
Battery under step selonoid by battery is this for system shutoff or emergency start? A solenoid in the battery box is normally the emerg. start, a charge solenoid (on / off, on / off) where the batteries are charging is a bad idea.
Selonoid under seat by converter ? Probably puts convertor on / off line.
Selonoid by generator Onan 4 k t start generator ?? The remote start solenoid.
Run / Store switch by door with light Takes house batteries out of circuit to prevent parasitic drain when not in use.
Any advice would be most appreciated.
In most cases if you go to the manufacturers website there's an archive of some sort where you can download all kinds of manuals for your rig. No charge, no waiting.
Ted 'n' Laurie, plus Jackson (aka Deputy Dog, the Parson Russell Terrier 'fur kid') and, Rylie (who crossed the Rainbow Bridge June 14, 2012).