Luddenites were 19th century folks who were so concerned about machinery putting people out of work because of its vastly increased productivity that they destroyed the machinery.
Foreign investment can take the forms you mentioned as well as buying companies outright. Investments increase the value of the dollar because they must buy dollars to make them. Japanese auto companies use this method called "direct foreign investment" as well as buy a lot of government bonds.
How long will foreigners keep putting money into the USA? Isn't the dollar going to fall against other currencies soon?
What about the concern that multi-nationals are setting up R&D overseas? If the RD is over there, where is the USA's comparative advantage?