late answer, and on 1.53, but I found your post just minutes before simply trying this:
to your user.js, if you want your tabsbar as wide as possible. It is "...toolband.Bookmarks.size" for the bookmarks and "...band.URL Bar.size" for the adress bar. Should work as long as your screen width doesn't exceed 3000px by far.
Edited 1 time(s). Last edit at 02/21/2010 06:46PM by SoerenB.