I passed SVA with that steering setup. I had a collapsible boss as part of the momo E30 wheel adapter. The chap did consult over lunch with the other testers but in the end the said OK.
The clamps on the steering rack are there to stop the brake cables binding anywhere on the wheels or suspension as that would be a fail.
Castor - as you said more on the back = works well.
Camber - I have 1.25 deg negative.
Toe in - I set to pretty much neutral, took it for a drive then adjusted in wards by a 1/4 till it was OK. I think for SVA I actually had a little toe out - whatever makes it self centre better for the test.
Bars over the exhaust? As long as they pass the radius tests the should be OK
