[Hodo]

Ok the idle problem does sound like the TPS going out. You may also want to do a throttlebody cleaning at the sametime.

Next the exhaust smell could be the breather tubes not being connected. But it could also be cracked flexpipes.

Headlights fluctuate with the RPMs.... Alternator going out on you. Not to uncommon. Check your powersteering lines make sure they arent leaking. Becuase they will get old and split and leak down onto your Alternator and kill it. And how do you know the rear swaybar has to be replaced. I dont hear of that going bad too often.... if ever. Usually its the swaybar endlinks or bushings. Also your IACV (Idle Air Control Valve) could be going bad, to options on this one... if your mechanicaly skilled you can take it off and clean it. (reminds me I need to do that) If you arent buy a new one.

Last thing, if your not sure when the timeing belt has been replaced get it done SOON! Replace the timing belt and the water pump and if it has more than 120K miles on replace the cam seals too. This will save the car for another 60K miles easily.

Goodluck and welcome to the wonderful and stressful world of the Z32!
Joy of driveing Generation Z!