Should the interior steel door be painted the same color as the room color?

I have kitchen cabinets that are peeling. The mfr has told me they were painted with “white polyester paint.” After I sand-paper the peeling surfaces, how do I repair the paint. Is there a primer I should use? What kind of primer and paint do I ask for? How many

I have contractors at my house replacing doors and painting the hallway. The doors which were repainted have a different feel then the previous ones. I believe they used flat paint and not semi gloss. I have kids in the house which will require finger prints to be cleaned up

I have a new fiberglass door and would like to stain both sides of the door. I realize that I must clear the door first. Do I need to prime the door first before staining? I am not impressed with gel stain. The two brands I have “tested” on the