I would add ... Clean the paint surface BEFORE you sand. Use soapy water and a cloth wipe to clean the paint surface, let dry and then use Wax & grease remover with 2 cotton cloths. Wipe in one direction with a wet cloth (wax&G remover) and then wipe with dry cloth before it drys.

You can get fish eyes but that is usually because of your inadequate cleaning of the paint surface.

I would use Lacquer based top coat as well. Lacquer has a different texture than enamel and it makes the paint look flatter than enamel. If you want to spray with a spray bomb then get a paint shop to mix up the correct paint /w hardener and use their specialty spray can to do the job. It makes painting easier and looks much better. Cost ~$50/can vrs $9/can.

Do many(-4) light coats of paint. This is better than 1 or 2 heavy coats.