Actual insurance appraiser here. Here's my take.
Insurance is all about risk vs reward. I would not drop your full coverage collision and comp just yet. You will not pay 5k in insurance over the next 5 years for the extra coverage, but you will lose 10k in 2 seconds if you have a momentary lapse in judgement and total the truck. Don't forget that you can also claim damage that happens while off-roading, as long as it's not a sanctioned event. I have paid tons of claims on 4x4's that where wheeling on private land and rolled and totalled. As long as you are not competing or in a sanctioned practice for a competition, you are covered by 99 percent of policies out there.
Can you afford to replace the truck right now if it was totalled tomorrow? Then you need full coverage. That's the simplest advice I can give.
I can't tell you how many customer cars got towed in, I call to tell them it's a total, and they cry on the phone because they just cancelled their full coverage a week ago because they paid it off. Now they are out 10k because they decided to save a few hundred bucks a year.