Switchable secondary voltages on power transformer?

[surfsup]

Considering that my princeton transformer doesnt carry a bias tap, would the bias resistor on the switch be necessary?

Are you doing fixed bias? If so, and you want to have the bias change when you switch HV taps, you might want to have the third pole on the switch and switch the bias as well - the resistor just drops some voltage before getting to the bias circuitry. It is shorted by the switch when in the other position, producing full HV voltage.