Countries like China and Canada are more dependent on the US than we are on them. We're in a position to negotiate the trade imbalance.
If the US stopped trade with China the results would be catastrophic for their economy. If China stopped trading with the US the results wouldn't be good but it wouldn't be catastrophic. Again, we're in a position to negotiate.
I do not believe this to be true. Trade includes services along with actual hard manufactured goods. The US trade pictures actually count on services more so than hard goods and have done so for some time. To that end, the US had a trade surplus with Canada in 2016, not a deficit. The US exports more agricultural products to Canada than it imports. Exactly how does the US win a trade war with Canada? You increase the cost for US consumers on the products you apply tariffs to, Canada responds by finding other markets for their products that have been tariffed which in the end lowers the available goods for the US in the future.
the fact that the US has such a large overall trade deficit means they cannot afford to just stop trading with countries who Trump claims are taking advantage of them. If they did so the standard of living of the average American would decrease since all the goods that currently are imported from China can either not be produced at all in the US or are much more expensive to produce. If they can alter their manufacturing to produce these goods albeit at a higher price due to labor and tariffs they have imposed on imported raw materials then the American public loses...costs rise, standard of living decreases.
And how does eliminating all tariffs help? The Chinese can produce goods at a lower cost as can many other countries. Removing tariffs doesn't change that picture. With no tariffs in place, the trade imbalance just gets worse as it is cheaper for Americans to buy elsewhere than in the US.
To some extent, the trade deficit in the US is a bit of a red herring. The economy is booming and unemployment is very low. Companies are not going out of business, in fact, most are doing quite well. Imposing greater tariffs runs the risk of upsetting all the good that has been done to the economy so far. The trade imbalance largely points to the fact America can afford to buy a lot of imported goods because they are overall doing quite well.