NB Suspension and Steering Questions

Taking delivery of a new to me 1999 NB Miata next week and I had some questions.

1. How big a deal is power steering? I was pushing the car around with the engine off and I could turn the wheel comfortably with one hand. Am I dumb to consider de-powering the rack?
2. How good are tein coilvers? I don't have part numbers, but there are definitely adjustable Teins on this car. My "squish the suspension by bouncing my butt inside the trunk" method makes me think the at-wheel, effective spring rate is somewhere around 8 kg/mm. 
3. How sensitive are NBs to scrub? The wheels the car comes with stick out to the point the slightly stretched 185/50/15 tires are pretty much "hella flush." Part of that is wider than stock wheels, 15x8.5 I think, but I'm pretty sure some of it is also wheel spacers and/or higher offset.  
4. Do NBs have low roll centers? The car is lowered a bit, but I think most of that is in the tires. The suspension itself looks to be about a 1 inch drop. Considering the pretty stiff springs already installed, I'm wondering if the massive upgraded swaybars are necessary and/or even helpful. 

Reference photos.
 

1. Not a huge deal on an NB. If you're planning to do autocross and/or don't like a workout when doing tight turns in parking lots you might want to keep the power steering, otherwise depowering it is totally reasonable. You should remove the inner seals, loop back the hydraulic lines and weld up the quill valve to do a proper depower.

2. In terms of damping, at least on par with than the cheap Taiwanese stuff like D2/Ksport etc. Not great but not bad.

Don't know about the other two.

Or you can take the main lines off, spin the rack back and forth to pump the fluid out, cap the lines at the quill, and loop the two ram lines together with a piece of vacuum hose, like I did in 2009 on my rallycross car.  That was about a hundred thousand miles ago and over a decade of rallycrossing.

I can't see a need to do anything that requires rack disassembly.  Seems like it invites more problems than it solves.  It's also not reversible. 

1. I wouldn't bother de-powering a street car.  I de-powered our NA because I was having issues with boiling fluid on-track with wide, sticky tires.  I've since re-powered it with electric power steering.  I don't see any meaningful benefit in de-powering a street NB, and I never bothered with ours.

2. Mediocre at best, but then I spent more on shocks than I paid for our NA.  IMHO everything around that price point is just OK, but not really good.  Really good suspension is pricey but once you've driven on it, you won't ever want to go back.

3.  Not enough to worry about with that setup... looks like 25ish offset wheels.  Should still fit with properly sized tires.

4.  The only way to find out is to sort what's there (good alignment, etc), drive it and find out.  Most Miatas don't need a big rear sway bar without sticky tires.

The Miata power steering is actually pretty good, providing good feedback at a decent weight.  We pull it off the Spec Miatas because we can't afford the minimal horsepower loss of driving the pump.  On a street car I'd leave it.