Just a few random comments IMO:
You are starting with a lousy combination of tire sizes so everything from there on is a major compromise. BioBanker, you may have reduced grip at the rear enough that it doesn’t understeer, but your front 205s define the limits of your car, and probably make for less predictable handling at the limit than if you had a more appropriate combination and less severe spring/bar configuration.
Those who corrected you on tire pressure effects were accurate.
Hot tire pressures of 30 psi? Seems low even for a street tire.
Reducing toe-out will help with corner exit, but similarly harm at turn-in. Not a good compromise I think.
Corner weighting is not the solution to under/over steer unless it happens only in lefts or rights.
Springs (and matching shocks) are for course tuning, bars for fine tuning and should be no stiffer than necessary, but you don’t have a wide range of spring rates available so get adjustable bars and try more camber in the front. Also, bars intrude less on creature comfort than do springs, making them more practical though less effective.
