If there should be no borders, why do you call the Europeans that came to the Americas "invaders"? If there boarders are evil and is an affront to "freedom" then those Europeans did no wrong by coming over to the Americas.
And if there should be no borders, then why should your personal property have borders? Why? There should be no piece of property with any borders and limitations at all! That is the logical conclusion of your argument. If a nation can't have borders, then there's no logical reason to believe that your personal property needs a border or boundary. And so there would be no such thing as trespassers or intruders or invaders, etc, because borders are against "freedom".
So you can see your logic is not entirely consistent across the board.
If you say the individual is sovereign, how about a group of individuals? How about a group of sovereign individuals decided to band together and draw a boundary around themselves? Is that wrong? If that is wrong, then you have no right accusing the Europeans of any sort of "genocide" as you have claimed.
Also, do you believe in evolution? If you do, then the demise of Native American culture and tribes is caused by the process of the evolution, the survival of the fittest! It is the same concept that plays out in the evolutionary process of our human race, so how can you fault the Europeans for advancing our human race through the process of evolution?
So I hope all can see how ridiculous these arguments were.
Borders is necessary precisely because we have private property and if you believe in libertarianism, private property is the key to your freedom. And guess what defines your private property? The border! Take away the border, you will have no private property and no freedom.