Power and torque go hand-in-hand. You probably can leave gearing alone since they already have a very tall gear. Pretty sure they can only do about 65... but they also have an electronic limiter on them.
It's been a while since I had last put some research into these.
They can't. The Roxor is not street legal but in some states it can be made street legal. It was part of the deal they made with Jeep when they got the tooling for the old CJ's.
They make about 145 torques but they are a turbo diesel... change some plumbing and the wastegate and you can have about double that power...
It's fun being a ride-along spotter... Seriously just as much fun as it is driving.
Especially if most of your driving ends up being FUCKING downhill for some reason.