Two painting questions

Factual Questions
1

In repainting a room, is one or two coats of enamel generally put on trim. The rest of the room, first painted when the house was buillt ten years ago, has been repainted with a coat of primer, and a coat of flat. I thought I read somewhere that repainting trim required only one coat in general. Is this true?

I also need to repair a small hole in the wall, and the original tinted paint was not properly sealed and while not dryed out, it is thickened. How can I thin a tiny amount of latex to repaint the injured area after I repair it?

2

In my experience, everything requires two coats. And why do you think you need enamel for the trim? What you need is semi-gloss or “satin” latex.

And you can thin latex paint with water.

3

When I repainted my living room, I used two coats on everything - flat latex for the walls and semi-gloss for the trim.