I don't know it all, but I've had some success and learned a lot from mistakes. Here's what I'd do.
In sanding down and filling with bondo on my Stargate build, I used around 120 grit I think. Now, painting right over that would show a lot of sanding scratches, but it was the grit I needed to get the job done, remove old paint, etc..
After sanding all of the filler, etc with that, I would spray a coat of primer - and that made some fine scratches and transitions to bondo apparent. I then sanded that primer flat with 220 grit I believe, again with the electric palm sander. For my project, and because of wood grain and wear issues, I sprayed a total or 3 or 4 coats of primer, sanding between coats. Sounds like overkill, but I was filling some grain in the wood and using it more like a filler-primer. Ideally, you'd only do a couple of coats of primer, sanding with 220 between.
Get a can of Naptha and use it as a cleaner/degreaser. Wipe, after blowing the sanding dust off, and before spraying primer. Wipe before putting the finish on it. Mineral spirits would work fine also.
Personally, I think the paint/primer combo is goofy. While that may adhere fine, I would recommend primer in a separate step, as it lets you look for issues, verify a flat (perfect?) surface, and give it another sanding step.
Not spraying? I've never used the foam roller method, but many have had success, so read what others have done.
I've had great success 'spraying' a latex finish, but if-at-all-possible, I would use an oil based finish, especially if you can get an off the shelf color, which you can. RustOleum, at least Lowes/HD around here, sells quart cans of oil-based black in gloss, semi-gloss, and satin, I think. I've sprayed those finishes and I think those would work well. I've read others opinions of this, and I agree - black, in latex, doesn't look good. On one project, the stenciled areas were black and I used latex black, since the base coat was latex. To make a long story short, I sanded it all back down and am re-doing it. Latex for the base coat (custom color, best I could find), but RustOleum oil-based rattle can paint for the yellow and black stenciled layers.
I use the oil based satin for the black areas, inner cabinet, top, back on a Williams cabinet and the sheen is awesome. However, for the exterior surfaces, I would rather use a semi-gloss, if you can find it. Using semi-gloss for the entire cabinet would still look good, I think. The label for that line of products looks like this:
Here's what the 'satin' can looks like:
I would NOT use gloss for a few reasons. 1 - it will look too shiny, compared to the original finishes you're used to seeing. 2 - it will show "every" issue in the wood. 3 - it will magnify any texture - orangepeel, etc.. in the finish.
If you can't find semi-gloss, I'd go with satin.
Not sure how many coats to cover, rolling. I've sprayed 3, 4 tops, for a base color.
I would wait AT LEAST a week, after painting it, before handling the cabinet too much.
Good luck...