Hmmmmm........
I just logged into my fidelity account, viewed positions, went to sell some shares and got to the preview all without issue.
But thats the world of computers for you....

I think Firefox is WIDELY accepted as a viable browser and has taken some usage away from IE.

In any event, I think the main answer is that for the most part, the Mac has a place and should not compromise your ability to create a site.