Question: Can Canadians on a TN visa: 1) invest in Roth IRA's, 2) buy a house, and 3) open a business in the USA? Also, can you work in the U.S. under TN status for two different employers? Can you get two TN visas - one for each job?
Answer: A Canadian citizen working in the U.S. under TN visa status may invest in a Roth IRA. There's no prohibition on this under U.S. immigration laws. Analysis of the financial advantages or consequences of this investment strategy is outside the scope of my practice. I would recommend consulting with a financial advisor for advice on this investment strategy.
Similarly, a TN visa professional may purchase a home in the U.S. There is no prohibition under U.S. immigration laws for buying a house. You should be aware though that this fact, combined with other evidence (such as pending green card application), could be considered a sign of immigrant intent by an inspecting immigration officer. Immigrant intent (i.e., intent to remain in the U.S. permanently) is not permitted under TN status. So if you're buying a home and have other signs of immigrant intent you need to be careful when you apply for or renew your TN visa status. But ownership of a home in the U.S. in and of itself should not be sufficient evidence of immigrant intent to warrant a denial of admission to the U.S. under TN status.
A TN visa professional may open a business in the U.S., but only in extremely limited situations. If you plan to remain under TN visa status, generally you may only open a U.S. business as a passive owner or investor. You may not engage in any type of employment with this business or actively manage the U.S. enterprise. To avoid complications and extra scrutiny over your business activities by immigration inspectors who may suspect you are engaging in impermissible employment, it may be more prudent to change status to a more appropriate non-immigrant category such as the E-2 investor visa, which permits a foreign citizen to open, operate and manage a business in the U.S.
You can work in the U.S. under TN visa status for two different employers at the same time -provided you obtain TN visa status approval for each employer.