Hi Brian, If you use flat paint you will not be able to clean it properly unless you mix polyurethane with it.
I would use a satin or an eggshell finish. You could use a semi-gloss but it will show all imperfections. I am getting ready to paint mine and I am using eggshell. I am considering adding polyurethane because I want to be able to clean them well and if you use it about half and half it looks like lacquer but you have to put on a few coats. The color I chose at Shermin Williams only had it in satin or eggshell. It really comes down to your needs and taste. I am going to put mine on here when I am done so everyone can see what cabinets look like when done this way or it could be a big disaster and I will have to start over. The life of diy. Good luck and get creative, that is the funnest part.
Yes. You could use flat paint and follow with a good sealer to protect the finish. I'd be concerned about a flat paint finish (alone) standing up to kitchen use, over time, as well as having concerns about cleanability.
Yes, but not very cleanable. Will show splatters a lot.
Brian...I see no reason you can't. To each his own!
You can do anything, but it's not a good idea. Flat paint doesn't wash well. You are better off with a semi gloss or gloss enamel for best wear and tear and washability.