What you consider to be a problem, others consider to be essential. The main reason I stay with FF (though certainly not the only one) is NoScript. It is precisely IE's inability to discriminate between scripting sites (so far as I know) on a page that keeps me from using it regularly. And I avoid sites that don't display properly without IE (less of a concern in IE 8).

Having said all of that, you do realize that you can disable scripts globally in IE? Which would still leave you with the same problem. You can also change fonts. And I'm guessing you can do the same things in Opera and Safari. The only difference may be that the people who use FF may be more knowledgeable than the those who use IE, since they probably know enough to figure out how to install and run another browser. So they are more likely to adjust options.

Therefore, I don't understand why you'd single out FF for your disdain. It's your users that are the issue, not the browser. And I don't know what purpose your webapps serve, but your users presumably employ them for their own reasons. So you can either deal with it or leave them to deal with it on their own (if you have that option)