A well thought out argument and right on, as indicated the only gray are is take property from a private owner and giving it to another private owner because it would generate more tax revenue. That is over the line without doubt but that is also not technically “eminent domain” either. If we use the “common Good” argument then there is also “no limit” to what the government can do as long as they claim its for the common good. Since the US Constitution and Bill of Rights was designed to “lmit” power the “common good” argument is on weak ground at best.