With any RV have it checked out by a pro. As far as going back to gas from Diesel many do for one reason or another, mine being size for small camp sites. As to maintenance the diesel will be about three times as much as the gas(there is a thread going on now on the subject with those who have owned both). Those that say otherwise are either not doing the suggested maintenance or just fooling themselves. I'm not saying one or the other is better just being real. The diesels usually ride better and get a bit better MPG, and are better appointed plus have more upper end options(more maintenance cost). If I were going for a DP again and I may, I would be looking at a high end older unit really kept well, they are around.
LEN