I'm not a Knoppix expert, but I think it's a little more stripped down - a live filesystem that you can boot up somewhere, like the floppy "tomsrtbt" distribution (with more tools, and features, of course.)

The suggestion above to check your hardware versus the compatibility list is a great one. Also, you may end up having to use something that's "just close enough" to work in a less-than full-featured capacity. If you really want to try some stuff, sometimes you can find a bleeding edge driver that may or may not work well. It can get pretty tricky sometimes, but I've rarely found a time that I couldn't make something work, with the exception of getting a decent resolution on a cheap-o on-board graphics hookup.

As for your specific requirements, without spending a ton of time to research every one, I'm going to make a guess and say you can do most of what you need here, if not all of it with a Linux distribution. I am not taking into consideration drivers or lack thereof, so checking that compatibility list will be beneficial (although you're most likely to find support for older hardware, such as yours).
Running Windows programs via WINE or VMWare is going to be painful. As in painfully slow... Perhaps you might want to look into Open Office,which, while not perfect, is pretty neat.
I can't really comment on the printing issue, but I'm fairly sure it's possible to create a simple postcript file on disk, then shoot it over to another machine (possibly even setting up print services on your OSX laptop.)
Since I'm not within immediate reach of a Linux box at the moment, I don't know if there's filesystem support for HFS+ in the kernel, but if not, you could always format the disk another way (Mac OSX and Linux can both speak FAT32, for example.)

Now, I know you don't want to hear it, but purchasing hardware can be an effective way to get a working system. I bought, a while back, an HP9000 workstation from eBay, which cost under $50 USD, including shipping. It was preinstalled with Debian GNU/Linux, which runs on that chip (pa-risc), although I can also install NetBSD if I choose so (or HP-UX, which the machine is built to run - I have an HP9000 running HP-UX, and I have to say it's quite zippy, considering the age of the box.)

Hope this helps a little - I don't have any real solid answers, but it shouldn't stop you from jumping right in! That's how many of us started.