I haven't ran across this specific scenario just yet myself. 

The issue is Detroit is a very block by block city so you’re going to want to narrow down your searches down literally to specific blocks within specific subdivisions and not just looking at zip code by zip code. so, while you can get answers of specific subdivisions that people may recommend, it’s best to make sure the specific block you are about to purchase the property on isn’t a rough one. that being said, happy to chat about Detroit real estate anytime !  

Is there a specific reason preventing the owner from selling to you outright?

There are  a handful of state specific experts here on BP and maybe we can point you in the right direction.

Speaking of which, I'm sure we'd all like to know the specific company policy regarding beers and barbecue when an investor is passing through town :P

I understand this can be fairly geographically specific.

Or are variances specific to the project?

I did some research trying to find a good detailed lease template to have my tenants sign but none seem to be specific and exhaustive in terms of covering any and everything that comes with the type of tenants that one finds in these type of neighborhoods.

So are there any specific pros/cons to home style vs choice renovation?

I did not specifically state any expected returns.