I haven't tried it, but it looks like this might address your issue with minimum tab width:
http://www.watchingthenet.com/firefox-tip-how-to-set-a-minim...
http://www.watchingthenet.com/firefox-tip-how-to-set-a-minim...
That brings me to another thing, the oh-so-cutesy "This might void your warranty" warning for about:config. I know they think they're being funny, but what would be a lot more useful is to actually explain whats going on, rather than scare users. I adjusted something for a less technical friend once, on their request, and they were slightly upset by the idea that Firefox could void the warranty on their computer. Seems rather immature, coming from the "Mozilla Corporation" with their flagship software...