I've seen painting procedures like these posted on different websites before, and I have to say that I think many of those steps are unnecessary. I know modelers are supposed to be natural perfectionists, but this is going a little too far.

First, what's the point of the primer? If it's only to improve paint adherance, I don't think it's needed. I use only enamel, not acrylic, and I find that it adheres to plasic surfaces fine without primer. I can understand the undercoat of white if you're using a color that is somewhat transparent, but depending on what color the plastic is molded in, that might not be necessary either. I know what you're thinking... "heresy! heresy!"

Also, it doesn't take "overnight" (lets assume 8 hours?) for paint to dry if it was applied by spray can or airbrush. Especially with an airbrush, the stuff dries almost instantly. A couple hours are needed for all tackiness to disappear.

The sanding steps are probably unnecessary if you have a good spraying technique. The clear coat is a good idea, but I don't know if I'd use Tamiya's. Regarding the polish and wax... well it's worth a try but I think you might be reaching a point of diminishing returns.

I wouldn't question someone who enjoys the "activity" more than the finished product, but I'm just saying that many of these steps would have an indiscernable effect on the finished model. I'm willing to bet that if you put two models next to each other, where one followed all the steps above, and the other followed my abbreviated procedure, the visual differences would not be immediately apparent.