As far as the "Only leaving the lugnuts exposed"
I also like this idea. It makes the pan a semi permanent mod since you dont have to take it off to check the pressure or take the wheel off.
I have positive results with something similar, simply taping up the wheels:
This seemed to help, but after a few months winds started tearing the tape and I took it all off. If I had to do it again I'd either layer the tape more or find some other way to fill in the gaps. I also had a lot of problems around the valve stem, to the point that I eventually took the tape off around that part of the wheel entirely.