Foreign investments should not be done at an economic level on a limited basis. Inward investment should be the jest of getting an economy back up and running in regards to combating an economic recession for an example. The money needs to be kept in the same country of output.
No, it is not economical to limit foreign investments, because people will not invest in the United States by force. People who have the money to invest should be able to choose where to use that money. Instead, the legislature should focus on making the business climate in the United States attractive to investors.