If you go to the Classic & Vintage forum, you will find tons of threads where folks have offered details and examples of resprays. There are, as you've found, a lot of details to it. The thing about spray paint is it is very unforgiving. It merely reflects what is there, so if there are any defects, expect them to show through.

Since you already have some topcoat on it, I think the thing to do is to sand down the parts you're not happy with and make sure that it is as smooth and consistent as possible. Clean the frame after sanding to eliminate any debris from the sanding as well as oils from your hands, etc.
Then respray. I've had better luck with multiple light coats, but you may have better luck.

If you can, let the paint cure in a heated environment. You didn't say what paint you used and whether it had a catalyst or not, but in most cases, paints benefit from some heat.