Everybody and their grandmother has done a list of Firefox features you would like to see come to the browser, but what features could you do without?  There is no doubt that fans of Firefox like a light browsing experience, so could Firefox do with a little house cleaning of features not used or loved by many? 
Security Zone Policy Errors – This seems to be more of a problem than most people realize.  From this one blog post, [...]

Well, I have always heard that there is no such thing as a bad idea. No matter if you think that is the case or not, there are more than a few bad Firefox extensions. Now I do not mean bad as in they will hurt you, I mean bad as in they are pretty lame ideas. So let us celebrate these bad ideas all at once, with the 100 worst Firefox extensions.
+ Did Your Favorites Make [...]