Agreed.
Not agreed.
Ok, then I have failed to make myself clear, poor writing, my fault.
Consider the Bible. For many this is their chosen authority. And they choose it because they consider it's statements to be binding on all of reality. The Bible doesn't claim there is a God for this solar system only. The Bible claims infinite power, the ability to accurately describe the very foundation of all reality, which is labeled "God".
If we wish to debunk this claim, we must first prove that we have an authority which is binding upon the realm claims are being made about, all of reality. And then we must demonstrate that god claims violate the rules of this authority.
So for instance, if we knew for certain that all objects in reality can only be round, and somebody proposes a square god, we can dismiss that claim. But we can dismiss it ONLY if we can first demonstrate that our method of knowing objects can only be round is qualified, reliable, PROVEN.
It's the simplest thing. Just present the very same challenge you reasonably apply to the other fellow's chosen authority to your own chosen authority. Such a process is called intellectual honesty, reason.
A process whereby we challenge the other fellow's authority while declining to challenge our own is not reason. It's ideology.
The two are very commonly confused, as both can involve logical arguments. But logical arguments do not constitute reason. Reason is defined by surrender to the process. In that way, reason is remarkably similar to faith, both are built upon a willingness to surrender to some higher authority.