This is a well thought out article, but it misses the main point that those blaming foreign buyers, and applying a tax on foreign buyers is nothing short of racism.  It is like the poll tax on Chinese up until the late 1940's, and the BC Securities act of 1942.  We have some bad parts of our history.  The US situation spurred by the Donald is something we must all fight.
The house flipping, and empty house  syndrome can be dealt in other ways, through CRA, capiital gains tax and full 100% tax for flipping  This is a business and should be taxed at the full rate , not the 1/2 rate.

I am not sure that a foreign buyer tax is even legal.  My view is that it should not be legal.