Its often easier to replace feathering shafts if you have 2 x 1.5mm hex drivers.  If you dont..you can always have a spare (2mm I think) long screw to put in where the rotor button screw goes to "bite down" on the shaft so you can remove the blade grips from the shaft without it just spinning.

I dont have a blade balancer.  I just use one of the grip bolts to bolt both blades together (level I might add) and then suspend the blades between 2 stacks of cds on the edge of the bolt.  I saw this somewhere online and it works and is cheap (FREE!)