We have 2 13.5's in our 2011 and it has not been a problem keeping cool. As for things to look for, I would say just keep a pad and paper in the MH and write everything down. After our shake down we waited till the end of the 1 year warranty to bring it back in, so a list to remember everything is critical. Good Luck!! I am sure you will love it.
Rudy - 10 year old long haired dachshund
2011 Georgetown 350TS
2013 Chevrolet Equinox toad