I have to agree with Fred. Whatever you've been doing so far is fantastic.
I don't know the answer to the hose question. Go online to an airbrush supply dealer, and ask.
As for thinning your paints, I'd recommend using the thinner that AutoAire, or whoever manufs. the paint, makes for that paint. Compared to the cost of your labor, the right thinner is cheap, and will insure that the paint behaves.
I use a hair dryer, not a heat gun, and I dry each coat, first on low, and then again on high. Trapped water will doom a lure before you even fish it, because it will cause the top coat to lift when it warms up and vaporizes.
If you did your lures without an airbrush before, I can't wait to see what your new ones are going to look like!