You should start using the search feature to open apps and see how easy or difficult it makes things for you. Though I do launch apps from the home screen, launching by search is something I use quite often so I don't have to track or remember which page an app is on.

I don't use the app for Facebook, since a browser gives a lot more control (on things like blocking ads, trackers, and still having messenger in the same tab). Sometimes I use mbasic.facebook.com from the browser for a messenger-integrated experience, but it's somewhat painful in certain ways.