Regarding your third paragraph, it’s been shown (anecdotally at least) that blocking access to these kinds of sites and fox news does a lot in bringing older, easily manipulated people out of the q anon rabbit hole. It’s difficult at first, but with nothing feeding the conspiracy, they go back to normal eventually.
I’m not sure if this was how it worked for reddit but it makes you set it up when first opening, then again when adding an account, then again for each new account. There don’t seem to be any global settings so you have to manually copy settings for each account. This makes it kind of a pain to set up how I want.
The admin at my first job did this but with an excel spreadsheet. They were old school and didn’t “trust” DHCP.