i am going to fill in holes and prime. should i apply a thin mixture of compound using a 1/2" nap roller and then paint over that or use one of the texture mix with the paint instead?

Yes you can apply drywall mud with a roller. You can thin it with water or even mix flat latex paint into it. I would experiment on some scrap wallboard to make sure it looks like you want it to. Once you have textured the wall you can then paint it with two coats of flat wallpaint.