Dear Mads,
thanks a lot for your post. It is very useful and I think can inform teaching the Wolfram Language. Here is a BarChart of the frequency of Functions used in all talks at the WTC2019:

I have often been asked to add a table with all functions that came up in a lecture (or just the new ones) by students in form of a table. This allows us to create a Wolfram Language Learners' Dictionary similar to books like this (for a natural language).
Thanks a lot,
Marco