Great analysis Sam, I completely agree. Ohio is a game changer, it is imperative that he win it and is the one I am most concerned about.
If Trump needs to open his wallet up more and pour resources in one state, it will be Ohio (and that goes for the general election as well). Just a key state for Republicans. I can't remember the last time the Republicans won a national election without also winning Ohio (and vice versa, I can't remember them winning Ohio without also winning the national election).
I can understand people in Ohio liking their governor but the stakes are too high to hand him a vanity prize. I say if he's doing well as Ohio governor, vote to keep him there but choosing somebody else for president - please!