Having worked on both the NB and many many many golfs of this platform there is a big difference. The NB would never get down to weight, but I think the mk4 could go on a diet and get pretty close to that min weight for ITB. The rear seatbacks alone weight more then the mk3 golf seatbacks. There is a LOT more insulation to remove. It does have 11.3 brakes, but camber will have to come strictly from the camber plates as there is no adjustments like the mk3 has at the spindle.

Motor is no better, gear ratios are about the same. The car should not be lowered too much if at all due to the front suspension geometry. Unibody is much better then mk3, but really nothing different after a proper cage is installed.

Disabling traction control is pretty easy, ABS is not as easy as some methods cause a complete limp mode. Good chip tuning support through the OBD2 port for instant programmming, though utilizing the aftermarket ECU rules and an early 99-00 drive by cable car would be easier then the later drive by wire cars. I dont know if I would build one myself, but I would definetly help anyone who wanted to build one up.