I certainly did response to your statement...
You said:
"Under the Protestant/Sola Scriptura (the Bible alone) theological system, is it your belief, and would you agree, there exists no person or no institution that can infallibly decide what is true and what is false for Christians when it comes to matters of faith and/or morals?"
And I said:
Pretty obvious per God's Own Word that man is accountable to HIM, and not a system devised 'by' men. Lord Jesus ENDED the Levitical priesthood of the old covenant system upon His cross when the veil of the Holy of Holies was torn asunder. Why do 'some' men try to put that veil back up, violating God's Own Word?
And that is exactly what the Isaiah 2:22 verse is about, God Himself speaking there...
Isa 2:22
22 Cease ye from man, whose breath is in his nostrils: for wherein is he to be accounted of?
KJV