English wikipedia on various aspects of 'British' history is pretty biased and prejudiced. There is the typical careful framing to tilt perception positively and negatively as required, such a desperate bunch.
The Romans weren't afraid to win wars by attrition. Some of their generals were definitely good but they could just swarm any opposing force with highly disciplined, well armed troops.
Hannibal crushed the Romans several times, it didn't matter. Carthage still got wiped off the map.
I'm no expert, and you are right he did leave sometime ago, perhaps there were changes with regards to protecting classified information after he left.
Classified information does not become unclassified just because it is publicly available if I remember correctly. Either way, I can't comment on whether including them in his slides is disclosing/divulging or not.
I didn't watch the whole thing just jumped around but he has included slides that are marked 'SECRET//NOFORN' so if that material is accurately classified at that level (and its disclosure was not authorized), well he probably shouldn't be presenting to that.
Of course whether those slides would cause 'serious damage' to national security is a whole other matter or maybe it was 'authorized'.
Well I'm fully on board with the notion that (workplace) diversity is overrated nonsense but this document could only be described as counter-productive at best. So things like this will only be used to justify the very thing he claims to be objecting to.
How unsurprising. Firstly, for most professions there are plenty of resources documenting what typical salaries are for degree/experience, so if you end up making less than that, well that seems like that is on you.
It flies in the face of economic common sense that if you could hire an equally skilled women and they would consistently accept 75% the pay as a man, then companies would have taken advantage of that fact. Just like they do with lower paid immigrant workers.