I have had worries about a couple of the things from your list too!
I have a cat so I have to vacuum the roof!
That has also resulted in me needing a car cover, the official ones are silver so will help with the heat too
There seem to be a coulpe of different ways to look after the roof, just wash with car shampo/plain water or use a treatment like AutoGlym for softops.
Have lots of fun
