Your OP purpose was to prove that Reformers do not depend upon Holy Scripture alone, to proclaim their faith.
Do with your OP premises as you will, but you will evidentually have to admit they do not truly represent Reformed apologetics, nor Reformed polemics.
Yes.. on the use of extra biblical sources.
No... I disagree about it being invalid.
Do you believe that God "Pre-Destined" mankind to two groups?
Elect and Reprobate