Mike,

You are well on your way! Keep in mind, HOK paint is designed to be put on with several thin coats, versus laying it on heavy. If you shoot it thin and light to build it up to full strength, you should be fine to mask over it within 30 minutes or so. If it has a little tack when you rub it, let it cure a bit more. When it's ready for tape it will feel dry to the touch with no tack.

I think you will be fine shooting it over plastic, but you might consider their adhesion promoter:

http://www.coastairbrush.com/products.asp?cat=79

I use HOK Kosmic Urethane Show Klear. I like it better than their UC35 clear. I fly electric, but I would think any of their clears are fuel proof.

http://www.coastairbrush.com/products.asp?cat=756

HOK paint is high dollar, but worth it.