After the fires have died down, Gorman is a much better destination. Literally hundreds of short trails everywhere. If you don't like the look of one, go to the next.
The Hummer will surprise you greatly. Most likely you'll run out of skill long before the Hummer's capabilities. As long as you have basic common sense (like don't go sideways when you're at a steep incline, etc..
), you'll have so much more fun than just driving to and from the mall!