1. How does Windows limit you?
No more than 10 concurrent connections to shares, limited number of physical cpus. Basically a lot of the things that distinguish the workstation versions from the server versions. There are other examples, for instance while I was looking into nmap for Windows I found out that MS had removed support for TCP over raw sockets in XP SP2 for no real reason. So there we have a cross-platform tool that is less functional on Windows through an artificial limitation.
Also, please don't assume I just meant Windows. OSX is probably the king of articifical limitation.
2. Torrents, they're the future.
By easily acquire, I mean easy access to legitimate copies. As far as I know Microsoft don't offer a general download version of Windows. I know there are student editions that you can download, but even these aren't a straightforward disc image.
3. I'll give you the malware point... however i've run windows all my pc-life and have never had these problems everyone else seems to have :/
I don't forget about malware altogether, but with Linux it certainly takes a back seat. I have clamAV to do the occasional system scan but it's mainly there to scan unknown usb sticks, downloads and attachments that may have come from/go back to Windows environments. As long as I download from the repository and keep my software up to date I'm quite confident I'll be fine with Linux. With Windows on the other hand I feel the need to have a real-time anti-virus product as standard to deal with files other people give me.
Also, don't take it as a dig at Microsoft/Windows. I'm typing this on a MacBook with Vista installed of all things and I work in a Server2003/XP environment and like using Windows. I'd be lying if said Linux was perfect, but it does give you options Windows doesn't.