For your EGTs, performance upgrade, I'd upgrade in this order
3" exhaust first, inside frame rails, with the biggest full flow muffler you can fit. They sound crap with no muffler.
EGT and boost gauge, boost controller
Tune,
Intercooler,
Tune,
Turbo upgrade
Retune
3" + tune should improve low end and midrange response, check your tune with egt gauge. Free flowing exhaust and a bit more boost will help reduce egts
As for lift, I had a 4"lift in my 80, now have a 2" lift in my 105 and sold sliders, same chassis, same tires, but on the 105 I modified the frame for longer shocks all round for more suspension travel. The 105 has been wheeled fairly hard and has been all the places my 80 went.
In big rocks, mostly you'll get hung up on diffs first, then rear control arm brackets, or tail shaft, then front bumper/frame rails or rear bumper. I reckon the extra lift really only helps with the last two.