Im not familiar with the tech specs of your coach, and am just learning mine, but I was an electronics technician in the military of 20 years on some advanced gear and can offer some general observations that may help.
Always start with most common failures and denomenators, don't assume multiple independent and simultaneous system failures without having evidevnce of a catastrophic event. It's much more likely to be a sequence of failures as a result of a common/shared system or component, ie. what do all these systems have in common?
It's pretty clear you had power regulation issues that has allowed some pretty high current to overheat your wiring/fry modules. Most alternators have internal regulators now. If those fail it could send high current due to unregulated voltage down the line to a fuse block/ breaker box/ invertor if hardwired direct. Not sure where the Power transfer switch fits in this sequence, but seems it would have at least a collateral relationship as it has to switch between the Alternator and generator as power sources. The dash radio should have been protected by a fuse preventing the wires from ever getting close enough to overheat/smoke so that's a collateral issue that will need to addressed to prevent future problems. The leveling system, etc. should also have been protected by fuses. If they weren't already, I'd install some ASAP. Visually inspect your dash radio wiring to see whether it was in fact smoking, or the smoke just exited the dash there. Do the same for each INOP piece of equipt. Look for potentially shorted and burned wires near each piece you remove. Pay careful attention to nearby harnesses that may have chaffed against the chassis at some point.
You stated the coach was stored without power, does that incude solar? Solar controllers could cause similar probs if they fail.
Assuming the coach was working fine when you parked it, you then also should consider the possibility of other environmental causes. Namely, rodents. It wouldn't be the first time a mouse has snacked on a wire bundle. Most of this is basic visual inspection stuff. Without schrmatics and a through understanding of your coach's systems and components it's all I can offer. Good luck.
