A tour of Detroit is a must; there's something to be said about experiencing the city in person; imagining what it once was like in its prime, observing the decay up close, the small pockets of rebirth peppered throughout, that can't be translated into a youtube video.
I would be happy to give you a tour, or at least give you some suggestions; pm me when you have your date finalized and if my schedule works out, I'll join you. I would allow a morning for the tour capped off by an early lunch/late breakfast.
Spend some time on this website to get you up to speed:
Experience Detroit -- Architectural Tours