I think I have read the same threads where the guy put down colour, clear, colour, more clear over and over. I really don't understand how that adds depth to the colours. Do all your colours and then clear it. If you wanted the 'flat as a pool table' result you probably need to block sand after a first coat of clear to level where the colours overlap then clear again.

I use Q-tips with Naptha to clean up after the stencil comes off.

Your second and fourth photos are not really orange peel, they are under spray and what looks like poor atomization. Higher air pressure and maybe less paint flow would help.