Good luck getting rid of IE. It's pretty well buried in the OS. Not sure why you'd want to, since it works better and faster than any other browser I've used.
Opera is not all its cracked up to be, it didn't display pages properly for me either, and they were pages I made myself without any "Microsoft Code". It seemed to have trouble with tiling certain kinds of tables. Maybe that is fixed now, I don't know, haven't used if for a while. I did use the beta for BeOS alot, it crashed frequently, but had more capability than the old Netpositive did. Now that a working Mozilla is out for Be though, I'm not sure there is much future for it. Just my 2 cents.