What are These?

You might get more knowledgeable help if you posted over in the Modding area and/or made your subject line a bit more detailed, e.g. "What are these tags in Filename.xml?"

I don't mod and haven't played much in the past year or so, so all I can guess even half-confidently is that a Government tag of 0 is Despotism. Crime might be an on-off toggle associated with an event or mega-event, and Cabinet might be a legacy string from a feature that got abandoned during development. But like I said, you need to catch a modder's attention, or maybe a serious Metaverse junkie.

They're all legacy strings, actually.

That must be a context thing I don't get. Governments are still in the game, and I could almost swear I've spotted some modders talk about tweaking factions to start with advanced governments.

That's correct, but "Government" as a value/ability has no game effect.

Yes, well, the context is still clear as mud to anyone who doesn't do mods or is just starting to learn.

Choosing to deploy government techs most definitely affects the game, and it seems like the faction XML would need to support a starting government level for the folks who build custom scenarios. But that's just an impression from reading about stuff that I never do myself.