OH and FL are in play always. not PA or MI
I think they would be in play with Trump.. its all personal opinion at this point...
I was mistakenly remembering PA as voting for Bush 2 at least one time, but after further review, you are correct, they have not voted for a GOP candidate since 88. So hypothetically, yes, if Trump makes MI and PA legitimately "in play", that would be changing the map.
That said (and back to your point that its just personal opinion/conjecture at this point), I really do not see him making a serious run at those states.
And again, the thing people really aren't talking about enough is the very real prospect that if Trump does get through the convention with the nomination that a GOP-establishment candidate files as a third-party candidate. A third party candidate taking even 5% nationally obliterates Trump's chance of winning any swing state.