It’s very likely that the admin in the school art department aren’t as skilled with their Macs (or they are trying to “over administrate” them). Safari is incredibly stable on OSX. Now, I will say that since the move to Intel I feel like Apple computers are a little less reliable overall, but I think that is a debate better suited for the hardware platform than the OS/Software, particularly since many of the issues are exactly the same as users of 32-bit Windows see.
Hate them? Well, there are plenty of art folks that manage to get work done on PCs, however among freelancers they are in the slight minority and in agency environments they appear in the vast minority. If you are headed the 3D route, you’ll probably be comfortable continuing to love your OS of choice, however if you plan to be outside of it you’ll likely never escape the Mac.
IE is a bad basis for comparison for any browser (unless you are making a case for why your other browser of choice is better). It has shit support for anything, and will continue to be the blackeye of Microsoft’s software efforts, as it continues to assume it’s the defining user experience for the internet. Nothing annoys most of the designers I know more, than dealing with “special” cases involving IE. It’s been that way forever.
I’m with Rusty, FF is THE browser to use, I just happen to still use Safari the most. The nice thing is, Webkit is going to become more and more commonplace under the current direction of browser development, and even browsers that are not Safari will begin to be faster, and similar in the positive aspects of Apple’s browser. Already Adobe has adopted Webkit for Dreamweaver’s rendering engine in the next release. I’m a fan of that.