Regarding (a), it depends on what your definition of "magic" is. In this case, the commands he uses are basic OTP primitives that Erlang programmers will encounter on a regular basis. IDEs and such create higher level abstractions that desugar to these primitives.
As soon as you encounter a primitive that the IDE doesn't handle on your behalf, you're lost.
One thing I would add to Joe's comment is that if you don't know what a command/function does, look it up. This is really painful in the beginning but pays off significantly as you hone your skills.
It's easy to bash IDEs for their coddling effect, and there are some legitimate arguments against them.
But looking up documentation is precisely one of the things that IDEs are much better at then text editors. Hover over some code and up pops the documentation. Plus you can usually navigate directly to the actual source.
Another example is "includes/requires/imports/pick your language". Typing those in manually is simply busy work that distracts from the task at hand.
Your other comment is also a strawman:
"As soon as you encounter a primitive that the IDE doesn't handle on your behalf, you're lost."
It could easily be replaced with:
"As soon as you encounter a primitive that you don't know how to enter in your text editor, you're lost."
Don't get me wrong. I agree that some aspects of IDEs, especially "Wizards", have a significant negative impact on developer understanding. But they also have powerful positive impacts as well that we shouldn't dismiss so easily.
As soon as you encounter a primitive that the IDE doesn't handle on your behalf, you're lost.
One thing I would add to Joe's comment is that if you don't know what a command/function does, look it up. This is really painful in the beginning but pays off significantly as you hone your skills.