Here's how you can change what your address bar recommendation shows: https://support.mozilla.org/en-US/kb/search-suggestions-firefox#w_enabling-or-disabling-search-suggestions

And for the search bar, maybe try fiddling around in customize toolbar, you can probably add empty boxes to force it to shorten.

Note that you can change the relative size of the location bar and search bar (move the mouse pointer between the two bars in normal mode to get a resize icon), but not the total size of this container as this is done automatically via a flex property. You can also move the search bar to the overflow area if you want to use this search bar and not the location bar. You can still access the search bar via its keyboard shortcut.

Thanks guys, I turned off suggestions and added flexible spaces to the toolbar.