Vice-presidential candidates do not swing states. I doubt that even a highly popular John Kasich as VP nominee will make a noticeable impact in Ohio. Whether or not Republicans win there, his presence on the ticket won't be the deciding factor.
And should the GOP ticket carry Michigan, it will be as part of a national landslide and not because of who the vice-presidential candidate is.
Exactly. Kasich has other strikes against him, but Rubio picking Kasich or another mid-western person simply for the sake of picking up Ohio/mid-western support is a false notion.