Well, the obvious answer to the initial question of this thread is the two rhetorical questions of "Is it legal?" and "Is there any point?", the answer to both of those being a resounding
*NO*.
It's illegal in the same way that it's entirely possible to use copyrighted music in a YouTube video, but you'll get done for theft if you do. I.e. it's piracy of something intended for only one use.
And it's pointless because one of the big reasons OSX works so well is it's designed for the custom hardware it's sold on, and
only that hardware. OSX running on a non-Mac PC will be no more stable - likely worse - than Windows on the same machine.
However, the same principle applies in reverse; install Windows 7 on a Mac via BootCamp (i.e. with all the custom drivers from OSX), and it will run
almost (it'll still be held-back by its reliance on a registry) as well as OSX - far better than it would ever run on any PC of equal spec.
In other words, if you want Mac OSX, buy a Mac; and if you want a PC... Buy a Mac!