Steering effort for manual 16:1 - should it be this high?

Caster helps with directional stability, equal caster, you go strait, more caster to one side causes pull.
The more equal caster - returns the steering to center harder, and turning is harder.
At speed, or moving it's less of an issue, in a parking lot, lotsa caster is a biotch .
My roundy- car has about 12* caster pass side, 3* on driver's side.
It always turns hard left, and requires considerable effort to go straight .

IIRC there is a 20-1 box out there.

There are also quick ratio idler and pitman arms, (iirc with 16:1 box and quick ratio pitman you get 12:1 or there abouts)are you sure your pitman is OEM non quick ratio?

I am no suspension guru, but doesn't caster keep the car driving streight, which for autocross would not seem to be a need.