Paint rollers will lose some of their fibers when they are first used, fouling the paint. I put the roller tube on a handle, put the handle in a vice to hold it with the roller up, and then hold a straight piece of 2 inch wide masking tape straight.
Run that tape back and forth across the rollers so the sticky side is pulling on the roller fibers and it will remove any lose ones, preventing them from fouling your paint. Sometimes you need to repeat the process with a new piece of tape 2 or 3 times to get all the loose lint fibers off the roller.
The ones that remain should stay on the roller, and won't foul your paint. I use the 3 pack of rollers from Home Depot, they've got white fibers with lime green plastic centers.
As for primer, I don't use any and the cab I pictured was bare wood before I started, it's actually a cabinet I built from scratch. The purpose of the first coat and sanding is to act as a primer of sorts.
I've painted dozens of cabs using that method, it's cheap, quick, and looks excellent. The comment I get most often is, "is that Formica?"