Idle Rpm High in Park, Low in Drive

That's a lot to digest. Can't believe the balancer does not have at least a TDC mark? You need to figure that out first and then get the timing right without the vac. advance. It can be added in due time. Vac is certainly high enough that the power valve in the carb is not the issue.

Another thought is voltage to the distributor. Not sure what that one needs, but if it's lacking, that may be the issue?