Some folks need a ladder to get to the ladder on the back of the coach:B
We need the ladder to get at the top of the slide, if we need to push leaves off.
Also for cleaning the roof, as I'd hate to step in a spot that had weakened. I used to walk the roof....now I climb the ladder, and just look!:)
As others have said, vent is just to allow use of vents when raining. A great option for the vent in the bathroom!
Really can't tell you what you need, because we don't know what you have already? Also, it will depend on your needs. Some folks need to have the Silver and China with them...others eat on paper plates with plasticware.
Walkie-Talkies are nice to have, if you want someone to help you with the backing of the RV.
Depending on where you are going, and how well you know the route, a GPS, a copy of "The Next Exit", and membership in one of the Roadside Assistance programs is a plus!