n general I agree with most of the things you've written. I also don't believe in tariffs as means for protecting jobs. And, if Trump were actually use them for this purpose I would object, and encourage Congress to take back the authority granted to Presidents in 1972 to act unilaterally.
What I actually think Trump intends on doing is to use the threat of tariffs to minimise dumping and the theft of intellectual property rights. BTW, the whole argument about "trade deficits" is a bogus one since trade deficits are offset dollar for dollar by capital excesses made possible by the trade deficits themselves.
Also, Mercantilism isn't balanced trade, it is an economic policy that calls for the use of tariffs and other non-tariff trade barriers to grow national wealth by ensuring that export value exceeds import spending.www.google.com/search?gs_ivs=1&q=mercantilism#tts=0