Hello Stu,
I'd call myself an enthusiastic amateur, my car is a road/trackday car so has different aims to yours.
just a couple of opinons as I don't know your experience, race series etc and we all have to find out for ourselves what works best.
The cross weights look good.
Even considering you're running the high spring rates of the D2's, I still wouldn't recommend going lower than 325mm, bump stops are found far too easily on our cars.
I'm not a huge fan of the D2 spring balance, its bascialy standard but uprated to reduce roll so low riders don't drive permenantly on the bump stiops. It still gives a balance to understeer. Consider softening the front rate or stiffening the rear, IMO the front but we're all different.
As standard our cars have a forward rake. Increasing the rear ride height 5mm to give a 15mm difference at the back can help shift the bias to oversteer on tight corners and understeer on high speed corners but its down to driver preference.
I notice you don't have the adjustable rear ARB, for the cost it might be worth considering to help fine tune the balance of your car. The front OE ARB is fine and should be left alone IMO.
The front to rear camber difference looks about right. As to the camber on the front, for track use I run -2.2 on road tyres but I've increased my castor to about 5degs that also helps. Looking at action photos this seems to work on my car.
After playing around I found by stiffening my rear ARB I could increase rear camber to give more overall grip but I then had to reduce my ride height to the 10mm OE difference again to tune the balance. Overall it improved things.
I don't know if your toe is truly zero but I like to errr on the negative between 6" to 12", it can help make the car feel more agile. I'd put this down to driver preference though.
I don't know if that's any use to you but its my experience and I'm always interested to hear what other people are doing to make their cars work for them so please do continue to post up.
Cheers,
Jim