Great analysis there Cameron.

I run basically a similar setup stated by Matty, with exception to front camber [I run ~3.75 neg degrees], front springs [275lbs] kings, 20mm front bar and increased track in front by 50mm.
I found that running the rear as soft as possible, the corner speeds have increased. I used to have a rear bar fitted [16mm] and the car would enter corner fantastic, mid corner was on edge and exit was oversteer city. Removed the rear bar and fitted softer reverse eye rear springs and the car was transformed.

I also run Falken semi slicks [RS-V04's] and only run around 24 - 26 psi.

As yet I haven't had any problems with understeer. I am toying around at the moment with having the H165 Diff housing Toe and Camber corrected.

cheers
benny