If you asked me in a different context "What religion are you?" I would say, Unitarian Universalist." But if you then explained that you were defining religion as one's highest values and that you believed that everyone who shares justice as their highest value shares a common religion, I would have no objection to that.
Why do you consider the definition of the word "religion" to be context-dependent in the way you describe?
Why would it be appropriate to describe justice as a common religion and not simply as a common value?
So before you go assuming that it's a "fact" that Muslims, Buddhists, and Christians would disagree, why dont' we identify some people in those groups who also say that they hold justice as their highest value, and ask them? Please realize that they do not have the same hangup as you seem to about being labeled "religious."
In general, no, though I have had some Christians get very upset with me when I described them as religious (apparently, they considered themselves to be in a "personal relationship with God", not a religion).
Most paradigm shifts are preceded by resistance. I hardly think the fact that some people are going to object is reason to avoid the discussion.
Improper usage of language is often met by resistance, too. The fact that people object to your redefining of terms doesn't mean that we're on the cusp of a "paradigm shift".
What I am advocating here is that we discard the distinction between "us and them" with regards to religion, and the only "polarization" that I am seeing is from people who want to preserve that distinction. So accusing me of being polarizing is a bit disingenuous.
It's not so much wanting to preserve it as acknowledging it exists. And I don't think it's sensible to ignore the reasonably foreseeable effects of your choice of terminology.
Would you be similarily shocked if a Russian objected to being called a "good American"?