First off your cam timing will have nothing to do with the accuracy of the balancer timing marks. You place a piston stop in the number one spark plug hole and rotate the crank until it stops. Lightly mark the balance with pencil. rotate the crank the other way until it stops again. Mark with pencil. measure the distance between your 2 marks. That is Top dead center Mark it perminantly there. As mentioned at this point mark the inner hub in relation to the outer hub to see if it slips.
Part of any good build is degreeing the cam. This verifies the cam opens and closes as designed and makes sure the proper advance or retard on the cam timing is as advertised. You can also use this to adjust the cam timing if you desire with different chains or offset bushings or offset keys.
Most of the time you can get away without degreeing the cam but it is generally part of any performance build.
good luck