Enclosed Trailer Questions

Side door for getting out of the car a must. Unless you like tantric yoga positions. I would replace the “new“ trailer tires immediately with good ones or specify that as part of the initial negotiations. The OEM tires are crap, I blew three of them very rapidly. As previously mentioned go 28 if at all possible. I carry two spares not one.
I like to use a winch instead of an escape door. It's nice to be able to drive it into the trailer but what if you're broke down?
Agree with loosing the crap tires that they all come with. I have never had an issue with Carlisle.
Get an electric tongue jack. They usually don't come with one.
If you want a generator slide out make one yourself, it's a lot cheaper. Lots of stuff you may want you can add yourself like extra D rings or E-track, pit pal stuff, etc.