caster brings steering feel and weight, and gives you more camber as you turn the wheel more. Think go karts.

On a strict track car running radial tyres Id go for:

1mm toe out
1.5 deg neg camber
4-6 degrees of castor depending on what you can achieve by modifying bits to pull the top of the strut back, or the bottom balljoint forwards

on the rear you might want to shim the axle where the stub axles bolt on to try and get 0.5mm toe in per side, 2 degrees neg camber