[ReallyOldLurker]

I suggest using the ESR version rather than the rapid release version: https://www.mozilla.org/en-US/firefox/all/#product-desktop-e...

I suggest learning about policies to manage the above mentioned annoyances: https://support.mozilla.org/en-US/products/firefox-enterpris...

Once you have fairly good policies.json it only needs an occasional updates. A backup copy is all you need to "instantly" configure any new installations.