A conundrum.
A 1994 is old enough to be old but not old enough to be a classic. So, personally, the interior painting your daughter wants to do won’t really effect the value of the unit as long as it is done well.
We had a 1986
Sovereign with the varnished doors and wall sections and we painted it white. Really brightened up the unit and made it seem larger.
I would not convert the twins to a queen. You lose the storage under the twins and whatever you gain in the center with the queen is difficult to access. I know that twins are not as “friendly” but they are but a short distance apart so visiting does not involve taking a cab…
As for the overhead, what you need i an automotive trim shop. They replace headliners regularly and can probably reattach yours or replace it for reasonable bucks.
When my exterior started to exhibit “male pattern baldness”, I just stripped it with Citri-Strip and then did a ridiculously light polish with plain old Meguiars Aluminum Polish. Followed by Walbernize. Was it “shave your face” shiny? Nope, but it was very presentable and easy to maintain.