I use Linux too and this should work on both Linux and Windows.
When you start with Firefox it has File Edit View etc. followed by a separator on the top row, then the rest of the row is filled by a flexible space and a little "loading" image. Then on the row below that you have the buttons, the location bar and the search bar.
What I'm saying is it should be possible to drag the flexible space back into customize and drag the url up where it used to be. This will mean the UI is only taking up one row.
When you start with Firefox it has File Edit View etc. followed by a separator on the top row, then the rest of the row is filled by a flexible space and a little "loading" image. Then on the row below that you have the buttons, the location bar and the search bar.
What I'm saying is it should be possible to drag the flexible space back into customize and drag the url up where it used to be. This will mean the UI is only taking up one row.
Like this: http://i41.tinypic.com/f7y9j.jpg
I don't know how to change the selection behaviour though. Personally I like having the whole URL selected but I can see it could be useful that way.