There are many many more submissive/masochistic men in the world than there are dominant/sadistic women

My guess is that this is true, but I'd be curious what the evidence is other than anecdote. Also, I wonder in the long-term how this will change. In popular media depictions, dominant females and submissive males are a common theme, so if people's sexuality is influenced by what they see/imprint at a young age (which is a standard hypothesis to explain fetishes), one would expect this to possibly change over time.

If you are smart and underemployed, you can very quickly check to see if you are a natural computer programmer by pulling up a page of Python source code and seeing whether it looks like it makes natural sense, and if this is the case you can teach yourself to program very quickly and get a much higher-paying job even without formal credentials.

I don't agree with this one. Python is one of the easiest languages to read certainly, but there's still enough conventions used in programming languages that someone could be a very good programmer with small amounts of training and have this not happen. This sounds possibly like an illusion of transparency or typical mind fallacy.