Christians are already divided. This was the result of Luther, Calvin et alii. The author wishes to reunited them.
We are united in Christ. Not an Earthly bureaucracy.
There has always been a Christian community outside of Rome. ALWAYS! Rome slaughtered countless Christians long before the Reformation.
Julius II and Leo X had absolutely no part I am sure.
What was the author saying about others "lacking a sensible view of Christian history"? Were you unaware that the East/West schism happened five hundred years BEFORE the Reformation? What was THAT about?