Spring rate help?

wstar

Ok so after all the other diversions, I still have a couple fundamentally-simple questions (one of which I already asked!):

1) Will I need to use shorter springs if I switch to a significantly stiffer spring and want to keep ride height and stroke about where it is today? Or should I basically plan on ordering the exact springs I have today, just in a different rate value? What would a normal person that knew what they were doing tend to do?

2) The rear sway: it's a given I at least need to cut back to the stock bar. What about just dumping the bar altogether? I know others have dumped the rear bar and been happy in 350Z's, but I suspect this was in combination with an upgrade to stiffer springs all around. What's the worst that could possibly go wrong* if I dump the rear bar and fail to do (insert some other unknown thing that needs to be done at the same time)? Would the car get unstable in some way that I'd really hate?

* - https://www.youtube.com/watch?v=20KJhBX9xtE

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