It will work just fine. Your wheelhouse is no different than any other 3600 rpm machine out there. You can peak over 6kw so it will run both ACs as long as you don't have a lot of other heavy loads running. Why don't you plug it up and try it for a few hours? Then you will know for sure.
Mess up his electronics? Really? Did his mom's stuff mess up while using it that week or so? I bet not.
Give the guy a break. If you don't want to hear it while he's boondocking than either address it to him at that time or move on. But don't feed him a bunch of******because you don't like his genny.