"None of those produce anything, they are entirely dependent on actual production"
They might not produce something physical, but then neither does a musician, or a writer. They're a part of the economy though, my entire point is that your link ignores non physical bits of the economy, but that is now the dominant part of the economy, so the theory is at least outdated.
"GDP per capita is just the GDP divided by population, and GDP itself is not necessarily about production at all"
How would you like to measure production then? Cars per person? Per nation? Is a Tata equivalent to Ferrari?
I know what GDP per capita is, that's why I used it, have you got any particular reason why I should be using absolute GDP figures?