I admire you and your passenger for perseverance. I can't imagine riding two up off road on rough stuff.
IMO if you have a repair issue that occurs while riding, there is a 99.9% chance it will be tire or crash related. Regular maintenance issues are the same on virtually any bike, lubricate and adjust and replace consumable parts.
The electronics are probably the most reliable thing on a bike and improve engine reliability, drivability and performance over carburetors. I've never heard of the electronics on a bike needing fixing. Other than the stater failing, which will leave you stranded irregardless, they do not normally ever fail during the life of the bike since they have no moving parts and are protected by fuses from shorts and overloads. They also make repair easier by recording fault codes you can use to track an issue. It would seem sophisticated electronics for ABS and stability control are here to stay. Engine management electronics have been around as long as electronic fuel injection. Some modern systems with a diagnostic port allow connecting with software on your phone (via a bluetooth diagnostic plug) to easily do all the things a garage can do like read and reset fault codes, read sensors, etc.
A 400lb bike is lighter than a 500lb bike because it is physically smaller which means less room for a passenger. Maybe consider getting two smaller/lighter bikes?
Last edited by twowheels; 11-25-2015 at 12:06 PM.