Painting Preformed 6-Panel Doors

I have just moved into a reasonably modern house (8 years old) and all internal doors are the hardboard preformed 6-panel type having a slightly textured finish. Some doors have had coat hooks screwed to them and the holes need filling and the paint has faded. I would guess that normal sandpaper would take the texture off.

Two questions:

Do I need to paint the doors? They are already white and the woodwork will remain white

How would I prepare the surface for painting?

Thanks

The doors will have aged over 8 years and will do with painting. The textured type cant be sanded to hard as you say because of the finish. A light sanding will get rid of any nibs on the surface. A good sugar soap down to get rid of any hand grease or nicotine etc. Undercoat and gloss or two coats of satin finish. They will come up ok.

Thanks for that.

Would wire wool be a good idea to get a key for the paint? Just thought that it is not too harsh that it will take the texture off but would key the surface.