As a followup, I went to a local offroad park (Hidden Falls) with a bunch of other Jeeps yesterday. I'm the low-rider white Jeep.
I took off the nerf bars before I went. I learned a lot yesterday. PO had a receiver hitch on there, and I need to take it off. I hit it hard on a ledge. Also hit the gas tank, as someone predicted. Didn't come close to hitting the rockers yesterday (thankfully), but I could see how that could happen. Was actually able to go everywhere that all the other Jeeps went - it's actually amazing how capable our stock Jeeps are.
Even before I went wheeling, I ordered two Solid differential covers. They were only $65 each:
Thanks for all the suggestions - very helpful