Does the dual control humidistat and thermostat on a power fan allow you to control moisture and heat separately?

You can control heat and humidity separately with the combination thermostat/humidistat on a power fan.

Yes. There is an off position on the humidistat that you can turn off during the summer. The thermostat runs from 60 degrees to 120 degrees so you would set the thermostat between 100 and 110 degrees and you would leave it at that position during the winter. The humidistat should be set on 80% during the winter.