#1: You've moved the goalpost. You "asked" how to boot a Mac from a USB stick, not for instructions on creating a bootable USB stick to boot an operating system not specifically intended to boot on a Mac.
#2: That a particular kind of computer has certain requirements for booting that are not, by default, met by certain operating systems, has nothing to do with freedoms. The requirements aren't hidden, they're publicly documented, and can be easily accommodated by those operating systems if their developers desire.
From my perspective, it seems like you're arguing that Apple restricts freedom because it doesn't follow 80s-era "standards" for partitioning and booting, but instead follows the newer EFI/GUID schemes. I find such a stance more amusing and ironic than credible, particularly considering Intel is largely responsible for both.
