I actually dual-boot Arch on my mid-2011 Macbook Pro, and two mouse buttons has been the least of my problems -- you can configure Synaptics to recognize a click on the touchpad with two fingers as a right-click, just like OS X. (You can even set it up to recognize a three-finger click as a middle click, which OS X doesn't do.)
The only real issue I have with Linux is that something keeps eating my bootloader, so I have to keep a GRUB boot CD around to boot into it.
Are you sure it's getting eaten? I have had issues with efi bootloader, where it'll forget to boot from the right OS but the bootloader is still there and accessible from the boot menu.
The only real issue I have with Linux is that something keeps eating my bootloader, so I have to keep a GRUB boot CD around to boot into it.