How to prepare redicote doors for painting

[Dengue]

I have purchased 5 big doors from Hume for a b.i robe, and they arrived with marks and some rough areas on the redicote surface.

I have had the edges cut to size locally, so need to prime the edges, and I intend to do the edges with a small roller, ( much less waste than spraying edges) and re prime the overall surfaces with an airless spray gun to make sure the water based finish coat actually takes to the primed surface

What level of sanding should I do on this pre-primed surface to get it ready for spraying a waterbased " 3 in 1" water based primer

[China]

If there are no highspots in the primer i.e. trapped dust or grit, then just wipe or blow the dust off