And would honoring that license require them to release the source for the non-GPL licensed parts of Xcode and perhaps require some action on any patents implemented in that non-GPL code?
They have to honour the license. Which provides and guarantees basic freedoms. But it allows the code to be reused in any project honouring the license. So your initial statement is false.
Nope, my basic statement is true. You didn't answer the question and by "code" you don't just mean the GPL code. The GPL tries to affect all code in the project not just the GPLed code.
