I own a 2703WS and as far as the Toilet goes, I have seen the same issue. Mine was caused by my stupidity by not putting a pressure regulator on the incoming city water. Do you use one?
If you are having odor issues with the unit follow Fonzie's advice and check out the Dometic model 300 odor problem and replacement
thread in the forum. I had to call the twice to get mine replaced but they finally came through. Delivered it to the house and it took about 30 minutes to put it in.
Never thought about putting stadium seating in. have you done it yet and if so please post pictures.
I was thinking about getting rid of the couch and purring in 2 recliners.