1. how much does a coil over drop kit hurt your tire clearance
2. do the shocks need to be changed to a shorter version
3. what is smoothest brand
4. how hard are they to install yourself if you have a buddy that works on cars
5. how important are the camber kits ??

 

Whatever the "drop" in the coil is, that is how much closer your tire is to the wheel well. You usually won't run into problems with any of the commercially available coils and stock diameter tires.

Typically no. Most drop coils provide less than 2" of drop. You will still be ok with your stock shocks and struts.

All of the answers to this will be subjective. A basic rule of thumb to follow is that the less drop you have, the smoother they CAN be.

Not hard at all. A couple of guys can get it done in an afternoon with a jack and basic hand tools. A spring compressor always helps. Some even think it is a necessity. You can usually "rent" one from your local auto parts store.

On some cars it is very important. On the xB, it really isn't. The rear is a torsion beam axle, and does not have a camber adjustment. (Sort of buying camber shims from OTG.) The front suspension geometry is such that a camber kit is not necessary, even with severe drops. Just make sure to get the car aligned after you complete the install.