Most all of the evil ware is aimed at Internet Explorer since about 90% of the people use it. It’s time efficient for the bad boys giving them the most bang for their buck. So I’m saying just give Firefox a try. It’s Free and you don’t have to make it your default browser until you are sure you like it.
The extensions are what make it great even though it comes with all that most folks need. I have 30 installed, but a lot are specific for web designers. Here is the Firefox Extension List so you can see whats available. People are writing new ones all the time and they are free.
I have a detailed page on PcHousekeeping showing my Firefox setup if anyone is interested and I try to keep it fairly up to date. It’s rare to find a web site that won’t work in Firefox. You will still have Internet Explorer if you have to access Windows Update.
Having two browsers is no problem even if you run them at the same time. I have Opera, Netscape, Firefox, and Internet Explorer and can run them all without problem. My default is of course Firefox and the others are just to see how newly designed pages look in each browser.