immortal1 (linn)
+1y
1. Would think the lower gear is the same. If any smaller or larger than the cam would be out of time. I say this as I DO know you can swap the entire head from a 2.0 to a 2.2 without switching the cam gear.
2. The harmonic balancer is probably different from a 2.0 to a 2.2 as I believe MazdaTweeker pointed out. As for the pulley itself, it can be different depending on what accessories the motor came with (i.e. power steering / air conditioning or not).
3. No help for ya on this one.