I'd be taking the unit back to the dealer and get the receptable issue resolved first, then take care of your next project, the exaust fan.... Make sure the ceiling is sturdy enough to support a fan and that you are able to find, or extend, 12 volt wires to your new fan. Then it is just a matter of following the directions that come with the fan. Cut a hole in the roof and install fan, connect wires and make certain it is sealed/caulked well with a good sealant. That is a simlification of the process. Make sure you think the whole process through before you begin cutting.
"If everything seems to be going well, look around, you've obviously overlooked something."