Part 1
I am sorry, but cannot answer your question regarding the factory installed system. Someone else may be able to. Most of the members here have gone the DIY route for RV SOLAR and you can find their systems and thoughts here.
Personally, I would look at only REPUTABLE 3rd party SOLAR suppliers (Renogy...) and start comparing price per watt. The Jayco Overlander SOLAR kit is $600 or 600/190= $3.15 per watt with a 30 amp PWM Solar Charge Controller. To me that is pretty expensive.
Apple to Apple comparison:
Renogy has a
200-watt SOLAR RV kit with a 30-watt PWM SOLAR CHARGE CONTROLLER for $349 (Free Shipping). The Renogy system (equivalent to Jayco's install) is 349/200= $1.74 per watt.
Really a no brainer. Even includes RV mounting brackets. (You will need some wire from controller to batteries)