I'm used to the assumption that my package manager is out of date. It usually is (e.g. it still has only OpenCV 2.4). I have a huge pile of PPAs to solve that ...
What is your strategy with updates? Do you give yourself permission to write to opt or do you run Firefox Nightly as root once a day so it can update iself? I tried the latter for a few weeks and grew tired. I can't wait for containers to come to Firefox stable (which is the feature I am looking forward to the most in nightly).
But you might want to consider a different distro with more up-to-date packages anyways.
It'll be consistently tested with those more up-to-date packages, so would most likely be more stable than your attempt to rejuvenate Ubuntu LTS or whatever distro you're using exactly.