Apple had been doing their own mobile processors for a decade. It was matter of time before they vertically integrated the desktop. They definitely did not leave Intel over the process tech.
Their strategy for desktop and mobile processors has been different since the 90s and they only consolidated because it made sense to ditch their partners in the desktop space.
Not this heavily. They bought an entire CPU design and implementation team (PA Semi).
The PA Semi purchase and redirection of their team from PowerPC to ARM was completely different and obviously signaled they were all in on ARM, like their earlier ARM/Newton stuff did not.