Hi Jack,
Re the sunroof - the quick way to check if it is a fuse is to see if the airbag warning light comes on when you turn on the ignition (above the light switch) - if that is not illuminating it will be the fuse as they share the same fuse.
Re the interior light - it should stay on for a few minutes then turn itself off - it does not go out instantly. If it is not that it will be a dodgy switch - nothing serious. I used to leave it switched off as I carried the dogs in the boot and would leave the tailgate or doors open when we stopped.
I had the loom in the o/s/r door replaced recently - so that would be the first place to check
Really glad you like the car - have had a lot of interest in it but I am really pleased it is local.
All the best,
Derek