My experience with tractors in the woods is that driving over brush and slash is a bad idea. Stuff gets lifted by the tires and jammed into places it doesn't belong. Pretty easy to tear hydraulic lines and filters off, puncture radiators, damage linkages, etc. Josh's tractor is more of an industrial machine, so it may be built to handle that stuff better, but in general tractors aren't designed to be used like that. You can add skid plates, which would be a step in the right direction, but you still need to be very careful.
This feller, Vince made this nice video about tractor logging with a small Kubota. He's in Boreal forest, so he has optimized his setup for that application, but I still think this is a groovy video. I would recommend 1.25 speed. He does actually use the tractor to limb logs in some situations, but it would still make me nervous, even with skid plates.