If this was not referencing "People" in a general sense why would the founders have complained about England searching all their shit and demanding papers?
Well, it is a generality, and it's not; we think of "people" a little differently than our ancestors did. For example, they didn't count African slaves as a whole person, rather 3/5ths of one (at least, for taxation and voting purposes), and Native Americans? Hell, they weren't people at all, but rather savages.
Also, keep in mind that the Constitution was written after the colonists declared independence from the British Empire, so the stuff written therein is less about "we want the English to stop doing this stuff to us," and more about "When we make our own government, these are the rules they'll have to play by."
Ben Franklin would have been expecting to be treated as a criminal in France instead of being treated as a free "Person". He did expect to be treated as a free person where ever he traveled as a diplomat.
I fail to see where someone's expectations while traveling abroad applies to the laws of another nation. Of course, to that end (and as I already pointed out), the fact that the Constitutional Amendments involving due process are written with that vague term, "a person," rather than the more specific, "The people," which actually supports my contention rather than contradicting it.
The language used in the Constitution and Bill of Rights is very intentionally done.
I don't disagree with that; what I disagree with is your supposition that the founders intended to give non-American citizens rights such as the right to bear arms, or the right to all powers "not relegated to the State."