The big questions
I don't know why
I'll get to that later
Pretty straight-forward, all of you know how to do this...I think. (sorry roux, petrus, and other non-cross method users)
Middle layer and free corners
Do F2L but the corners have any choice while the edges have to be matching the centers. And the edges have to be oriented correctly.
Do OLL then PLL, if you end up in an unsolveable state relative to the yellow side, do M2 U2 M2.
Do regular PLL.