What are the effects of abolishing the minimum wage?
So this is a very broad topic. There are arguments pro and against minimum wages and there are many variables to consider.

As for your question, arguments 1-3 are basically argument 1. A higher minimum wage can limit employment / increase unemployment among people whose hourly value of labor to the employer is less than the minimum wage. As a result, those people may also miss out on increasing their value of labor, by missing out on work experience. That much is true. However, it does not mean that there would be zero unemployment without a minimum wage. For example Germany did not have a minimum wage for many years and still had unemployment. This is because there are other reasons for unemployment as well, like skill mismatches, search costs (frictions), reservation wages, etc. 

Argument 4 is basically speculation. There is no guarantee that jobs would return to the US without a minimum wage. People will still have reservation wages below which they will not offer their labor and those reservation wages could still be above the current wage in another country. There is also no guarantee that automation would be significantly halted if the minimum wage were to be abolished (although the speed might slow down a bit).

For the sake of fairness, there are reasons economists would favor a minimum wage. One reason could be for example the presence of a monopsony (one dominant employer) and some would argue that is what Walmart has in certain regions.

Suffice to say that there is no clear answer on whether the minimum wage should be abolished or not.