I used that to custom harden my installation of firefox, but I forgot what the link to that site was. If anyone knows, please help.
The only one that comes to mind is this one About:config entries - MozillaZine Knowledge Base.
How do you decide what to change and what not to? I’m guessing you need to know the implications and need case for each change?
I just installed Arkenfox and then changed settings that annoyed me while using it, such as deleting history on shutdown. I also switched from FPP to RFP. I don’t have much knowledge regarding Firefox settings, so I only changed things I understood.
I did the same thing then discovered a new fork of arkenfox that takes privacy and security to the next level. They also do releases the same time arkenfox updates to include the new changes in arkenfox. It’s a perfect fit and I highly recommend it.
Narsil user.js:
Do people manually update this user.js? or run the script every time rebooting or something
There are multiple different approaches you can take, personally I usually manually check for updates with the updater script after a new release of Firefox (every 6 weeks or so). Sometimes I’ll skip a release cycle or two if not much has changed or if I’m focused on other things. On linux it wouldn’t be difficult to automate, but updates are infrequent and II don’t mind doing it manually so i’ve never bothered to automate it.