I understand your concern with not having another platform to deal with but as a Mac user of over 15 years, I would be hardpressed to switch to anything else.
First: Simplicity—you control the computer, it doesn’t control you.
Don’t like the zooms, etc. Fine, just turn them off, one click. Set your own background, make your own icons, etc etc.
Second: Bill Gates has to learn that we all don’t want to march to his drum. IE is terrible (Safari is OK). Why do people attack Windows with viruses and not Mac? You rarely will find a Mac virus interrupting your work.
Third: It works. I rarely ever freeze or crash—its not perfect but the problems are definitely fewer.
Fourth: Cost is definitely a factor—Macs cost more BUT balance that with time lost on Windows and its myriad of problems. (Plus constant downloads of patches, fixes and hacks).
There are other reasons to switch but those are the ones that touch me the most.
As for a CSS app—I recently purchased Style Master from WestCiv and it is a very nice program.
As far as HTML text editors, I don’t think anything beats BBEdit and it is only for Macs.

P.S. I just finished your CSS Anthology—great job! It was excellent; thorough and easy to read and follow.