What we now call trade is not really trade. Dismantling a plant in the US and shipping the equipment and jobs and technology to Mexico or China is not trade. That’s capital transfer, or asset transfer. Then products once produced in the US are produced there and shipped back to the US for sale.
That’s not trade. So if the owners of capital can move their assets and production around the world, why should labor not be able to move on the same basis? It’s all a bastardized system that is no longer trade of goods and services, but transfer of the factors of production to the benefit of some participants, but not all.
I predict that someday all the supporters of this so-called free trade will prove to have some of history’s most useful idiots, because if something doesn’t head it off, so-called free trade will have been used as a step in erasing national borders just as it’s been used in the EU.
And the reasons you give in #7 in opposition to the free movement of labor were once given in opposition to the admission of goods from cheap labor nations into the US. The impact of the free movement of cheap goods and the free movement of cheap labor would be very similar. Both upset the established order and benefit some and harm others.
You might find this article interesting.
http://www.plata.com.mx/mplata/articulos/articlesFilt.asp?fiidarticulo=194