The mortgage guy told me the other house would be treated as an ADU and give me no real value towards the value of my future mortgage.Not sure if that helps much?

One thing we, as humans, are consistently bad at is predicting the future - especially when it comes to political and economic shifts. 

Of you can relocate and house hack, I highly recommend that so you give up less cash upfront.Good job not spending your stack on some bad *** pick em up truck or other nonsense young people would otherwise spend it on! 

I would pass on this deal given the red flags you share (and the fact you feel there are red flags is generally a bad sign).

Unfortunately, those are treated as personal expenses and aren’t deductible.As for the repairs and improvements, fixing leaky pipes counts as a repair and can be fully expensed in the current year.

That sounds pretty straightforward and we've got something similar here too and it's not bad. 

All complimented with Amazon fulfillment centers, google, and more tech manufacturing jobs.The bad reputation of “Detroit” comes from OOS investors wanting sub $40,000, D class properties in poor condition, because they pencil out to 2-3% deals on paper.

So, for items #1 and #3, I would talk to them directly first because I like to treat people like people and communicate directly about anything.

Doorvest claims that they help identify, purchase, and own rental homes for a littles as 35K and help generate cash flow.At the moment, I'm little skeptical but wanted to give it a try and write each steps here (good or bad) and help the community here. 

The way that things like this are typically handled is that if a lawsuit were to happen, since both people have been behaving under the assumption of a lease (the landlord renting their space and the tenant paying rent), they would probably treat it as if there was a standard month to month lease agreement.