#1
A buddy of mine and I ripped apart my cheap old Squier Strat just to see if we could try and mod it and such. I've noticed while putting the bridge back on that different guitars have a different number of springs in holding the tone block and also different arrangements of the springs.

Is there a normal number/alignment for the springs or do different guitars just vary? Right now, I just have all three parallel with space between them. Is that good, or should I try something else?

Also, we accidentally ripped the ground wire off of the tone pot, and now neither of us can remember which pot it went to. It looks like the middle one (if you're looking at a strat's control layout), which i think is the neck pickup tone pot. Can anyone confirm which pot it should be soldered to?
#2
More strings = stiffer whammy action, more tuning stability, and will make it a 1-way trem. They might be needed if you're playing with 13s--dunno; I haven't had anything more than 10s on a Strat. I use STHB on some SuperStrat guitars, and they're fine with 3 springs--I did need to get shorter screws to get the claw tight enough, though.

3 parallel or in a triangular pattern should work for the main part.

It doesn't matter that much which pot you solder the ground to. Even volume pot would be OK. For the sake of wire routing, it might be best to put it back where it was. If you look very close at the pots you should see evidence of where the solder ball used to be. It might be duller than rest of the surface, or slightly discolored.