Glad you got some trail experience. There's no substitute for being there and doing it. It struck me, though, that you said you only used 4hi once (presumably meaning you never used 4lo at all), and that you hit your running boards and your diff a couple of times.

Those might be related. When the road gets at all rough, don't hesitate to drop into 4lo. Lo-range isn't just for climbing steep hills, it's also for controlling your speed so you can maneuver over tricky obstacles slowly and carefully.

Whenever I'm on a dirt road where my top speed is likely to remain below 20 mph, and there are intermittent obstacles that require 5 mph or less, I leave the vehicle in 4lo. It just drives much better that way.

Of course, a spotter is also invaluable as you are getting the feel of your ground clearance, and learning just what obstacles you can drive over without hitting.