I suspect that Trump will win Ohio (and any state) if polling is tied or within 1/2 points in the state going into the election. Practically every poll in this so far has had huge quantities of people in the "undecided" and "someone else" categories, I would bet that many of them (not all) are embarrassed Trump leaners.
Clinton's lead is pretty secure and she should win, but I wouldn't be surprised if Trump outperforms his polling by 1-2+ points across the board.
Undecideds broke away from Trump in almost every primary before New York.
I think these are two different classes of voters and where they overlap they are facing a different choice.
Nationally you are correct, but I have read the best ground game in OH is Portman's and that should help Trump.