I actually DID the JPR at Manassas National Battlefield Park a few years ago! I had a blast! The obstacles weren't TOO tricky in my opinion its just a matter of you and your horse having good body control and trust.
One obstacle that I thought was great was "rescue the wild animal"
We came across a hurt stuffed animal, had to dismount, then remount with the stuffed animal on the horse and carry it to safety.
The main obstacle I struggled with was doing the perfect circle while holding the rope...I didn't have enough body control and my horse didn't know how to neck rein...we got a 1 for effort on that one LOL!
Try it out, go in with an open mind. I still have quite a few friends that live in Clifton VA and do the JPR at the battlefield. I moved to Ohio so I don't get to do it anymore :(