I find I can get about 2" from fully inflating the supplemental air springs, it helps some.
Adding rollers is problematic, they usually reduce clearance (else the accomplish nothing) so that you hit the frame more often, but you don't hear the scraping noise.
If you start towing anything, you are going to be hitting more often, at least from the extension of whatever you put in that hitch, and usually because you will need a significant drop at the receiver to get the hitch at the right height for a typical tow.
The real solution is to start learning how to adjust your approaches to dips and driveways so that you seldom drag. That's not easy.