I would recommend running untrusted proprietary software as a webapp if possible, it will not be able to be as intrusive in that case compared to native app even with all the sandboxing (flatpak, snap, etc…). Or Virtual machine as the most secure option, but it may be overkill.
Not surprising for them to drop MV2, I expected it to happen even sooner, you would have to go out of your way to support MV2 extensions on chromium based browsers, and I do not see a reason for Microsoft to do that.
I get the impression that people want MV2 primarily for better ad/script blocking, but maybe the more secure and efficient way to go is to have built in adblocking. Firefox recently integrated adblock-rust, but you have to enable it in about:config and add filters manually, it seems very experimental and barebones at this moment compared to how it works in brave, for which it was written originally. It is probable some firefox forks expanded on this feature.
Fascist and colonial states atrocities are widely documented in Wikipedia, countries that we consider capitalist probably too. I recently stumbled across Belgian atrocities in Congo reading Wikipedia by accident. It motivated me to read more about it in the future, maybe “Heart of darkness” (while not exactly historical, it still seems like a good critique. By the way is it a good novel?).