Ive used Testors Military Flats model paints since the 60's, and always had good results. Lots of colors to match pretty much any pattern you might want to try and duplicate.
Holds up well, and is easily touched up, if you feel the need. I have one gun that was painted over 25 years ago, and has had a good bit of use, never been touched up, and still going strong. It shows wear in heavy contact points, but thats to be expected.
Comes off completely with a little work too. Ive also stripped another gun a few years back, that was painted at the same time, and the bluing underneath, was about perfect. The only spots that showed any finish wear, were a few small spots that had the paint worn through.
I have tried some Krylon with the last couple Ive painted, and its been OK. The colors arent consistent between lots, so just dont go by the cap, or the last can you bought.
It seems to come off OK too, but I didnt use the "Fusion" stuff on plastic, so Im not sure there.
Ive used Alma Hyde II, on all sorts of stuff, and when applied following the directions to the letter, its tough stuff, and works great. Its not coming off short of a bead blast though. Ive used it for a base on a couple of guns, and then Testors on top for the patterns. I later removed the Testors, and the AH II was ready for the next pattern.
I used to take things apart to paint, and still would for somethings, depending what i was doing. Anymore though, I just tape off what i dont want painted, and have at it. Just degrease good, including your hands, and paint away.
Ive been into Multicam of late. Its one of the easiest patterns to do, and works great in the field......