You might check the American Expeditionary Vehicle web site and look for their information on springs.

Keep in mind they reference the TJ/JK springs. However, the ZJ should not be much different.

Spacers will help and I did not find them to impact the ride or drive of my Cherokee. I used 1" spacers.

Any lift will change the steering geometry. Go for the adjustable track bar.

Don't know about the control arm issue. My Cherokee 3" lift came with new control arms.

If you had the factory tow package, you may already have the heavier springs. Again, the AEV website has very good writeup about springs.