Hey mate love the car.
I drive a 2004 Ti-L as my daily driver, I have an RB25det 240Z, used to have a 300ZX.
Get an Alutec Strut bar for your X-Trail it will be the best $250 you ever spend on it. I run standard Suspension.
I drive my car 43km to work each way on a Targa Tasmania Stage. The strutbar takes all the chassis tram out, I do not have juddering front wheels now when I take a corner hard.
The Xtrail does not get me to work much slower than the 300ZX used to and it is corners all the way. 25mins-30mins to drive 43km (at the speed limit roughly, on windy roads plus 3km of gravel)
I also upgraded to Bob Jane 19" rims with Federal Super Steel 595, 245/40ZR. Holds like crap to a blanket now even in the wet. I am always catching up to cars not them me.
You will have to be careful with your rim selection for your X-Trail, Bob Jane would only sell me Load Rated rims for my Xtrail, but for some reason with the 2002 model I do not think you have to have Load Rated rims.
By the way I only skimmed through your build. Do you have a set of exractors for a non turbo X-Trail?