Arkenfox has a good user.js [0] you can use. Each comment tells you what the option their disabling is.
I had been putting one together based on it for newer machines (and it worked great), but just now when I went to look for it, I'm not sure what happened to it. Sorry I can't share mine.
If I recall correctly, you just plop the user.js into your profile. You'll want to do it from a fresh profile* and then any time you want to make a change, you'll make it in user.js instead of about:config. What I believe happens is every time Firefox start, it applies all the configuration options specified in your user.js.
[0]: https://github.com/arkenfox/user.js/