Well, although I haven't received any replies, I'll post what I've found so far:
The o-ring and flush didn't fix the problem, maybe ever so slightly....
The majority of the problem was the steering knuckles. after blasting them with WD-40 with the wheels off the ground and really working it in, sure enough my steering feels like a dream.
I can't say if this fixes the speed related portion, but it moves so nicely that the weight of the wheels centers the steering if I let go of it.
And that flush job shocked me, after even being forewarned. I managed to put a gallon of fluid through it in 10 seconds flat.
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1994 SVX LSi - Black / Beige - 139k miles
SOLD! 
1999 Chevy Camaro Z28 - Black, 6-speed, hell of a ride.
2004 Chevy Silverado Z71 - Blue LT2 luxury package