This is a very nice build journal. You have definitely made some good improvements over what Hobbycraft originally gave us in the box. I have two of these P-36 kits, but none of mine have the fixed landing gear. I really like what you are doing here.
As far as the lighting goes, it's a personal preference. I like to have the model placed in between the light source and me when I spray them. That was I can see the spray pattern easier. This is especially true when spraying on a clear coat. If you rotate the model in a manner that allows you to see the paint as it actually lands on the surface, you can see how the paint is flowing onto the plastic. This helps to eliminate any shadows or thin spots in the final coat. It doesn't matter when you are doing a camouflaged pattern such as a Luftwaffe mottle, but it is very important when you are spraying a large area the same color.
I have tried to paint with the light behind me, coming over my shoulders as the others have mentioned. But for me at least, all it did was block the light, as I actually cast a shadow onto the model and blocked the lighting. I mounted two different lights on the work bench on the opposite side of my seat, and the problem was solved.
I don't use a spray booth, but I should. I'm actually thinking seriously about building a spray booth with some small lights inside it... That way I'm not painting in the dark...
Here again, it all depends on personal preference, and if you are painting inside a booth or not.
Hope this helps.