Comment by Throwthrowbob

I use user.js to disable the suggestions, but this doesn't help on initial install and running of Firefox. It's among a over a hundred or so options user.js sets (and reset every startup) that I use to maintain my Firefox.

user_pref("browser.urlbar.suggest.engines", false);

user_pref("browser.urlbar.suggest.importantDates", false);

user_pref("browser.urlbar.suggest.mdn", false);

user_pref("browser.urlbar.suggest.quicksuggest", false);

user_pref("browser.urlbar.suggest.quicksuggest.nonsponsored", false);

user_pref("browser.urlbar.suggest.quicksuggest.sponsored", false);

user_pref("browser.urlbar.suggest.recentsearches", false);

user_pref("browser.urlbar.suggest.searches", false);

user_pref("browser.urlbar.suggest.sports", false);

user_pref("browser.urlbar.suggest.topsites", false);

user_pref("browser.urlbar.suggest.trending", false);

user_pref("browser.urlbar.suggest.weather", false);

user_pref("browser.urlbar.suggest.yelp", false);

user_pref("browser.urlbar.suggest.yelpRealtime", false);

Updates: there is a policies.js option that allows one to take control of updates.

"DisableAppUpdate": true,

On Linux, placed into /usr/lib/firefox/distribution/policies.json