Congrats on your new to you coach. The short answer to your first question is no. I have not seen this prewiring on any DS coach of that vintage.
Adding an inverter is always a challenge. Consider:
1. Having as many coach batteries that can fit in the tray (quantity and height).
2. Determine the circuits that will be on the inverter and run wire accordingly. If you want everything but the HVAC units, on the inverter, take a good look at the battery capacity you'll have and determine if that is a good idea.
3. From the inverter to the power source will be wired according to the instructions that come with the inverter.
4. As to the auto generator start, I have never done this. This may be a separate project from the inverter.
5. As to the remote control panel, consider going wireless. The fewer wires one must run the easier the project will be.
6. Inverters have their own breaker for the outbound power. This is around 30 AMPS. This example means all the circuits power by the inverter could draw a maximum of 30 AMPS. Take this into consideration when determining which circuits will be on the inverter.
Go to http://www.magnumenergy.com/Literatu...lent_power.pdf
help in choosing an inverter.
Go to Power Inverter, RV Inverter Charger | RV Power Products
for a sample of an inverter.
Choosing which inverter to use will mean Googling "motor coach inverters" and reading about the feature of the different brands.