I can help you out with a few of those questions.
4. Yes a white base coat will make the glow colors work better. Another way is the use the regular color of paint as the base coat instead of white and you will get a deeper glow of that color. For example, put a base coat of regular yellow chartreuse on and then the glow yellow chartreuse. To keep your base coat from running, I would suggest a fluid bed as it will put a real thin coat of paint on the jig.
5. When using a toaster oven, get an oven thermometer to verify that your toaster oven is heating up to the right temperature. The one I use is off by more than 50 degrees according to the dial on the front.
6. A heat gun is definitely better than a propane torch (safer too). What we use to preheat the jigs is the toaster oven. Just hang your jigs in the toaster oven and let them preheat for 15 - 20 minutes at 375 degrees. If you are only doing one coat on the jig and opening and closing the door of the toaster oven a lot, raise the temperature to 400 degrees. When doing multiple colors, we take the jig out of the toaster oven, dip it in the fluid bed, and then use a craft brush to sprinkle on the additional colors. By the time we finish the last color, we hold the jig over a heat gun to smooth everything out. Then hang the jig back in the toaster oven when yu are done to cure, You will want to be careful curing the jigs if you use multiple colors.
Hope this helps. We have videos on our website that show this process. Check them out at Welcome to TJ's Tackle. Let me know if you have any other questions.
Thanks,
Benjamin