Jaked; After reading these posts I think it is time to start testing yourself. Then you will know exactly what is what. Not hard to do, recommend two people just in case.
Strange things do happen.
The ones that would worryy me would be : how does W/D drain and those Black tank flushes. We all have stickers warning us about using the black flush. Basically to open valves and output terminal. Seems like if those two Two black tanks are being sprayed at the same time could be an easy accident waiting to happen, oops main black full but hardly have used rear toliet so start dumping washing main and forget to open flush rear. Seems like you will have to have a "Y" two sewer hoses attached at least for black tank flushing.