Do they like to be on the couch (if so I have couch covers)?

Maybe a major news outlet would be interested in covering your story. 

Also note that my company will possibly either cover closing costs if we sell or provide property management for two years if we rent.

Hopefully the deposit covers Jan rent, make sure you give them an itemized list of the money owed to you for any damages or unpaid rent. 

Doesn't exist.. can you get lucky?

Prior to inspection I replaced one outlet cover.

I have 2 options:- finance the construction pre-selling the apt, and take my profits (expected to be around 700K pre-tax); or- finance the construction with a 6-7%/year loan (collateral = my house), keep the 10 units, and once the building is completed in 24 months, rent them for circa 180K/ year gross.

You have to have an "existing relationship" if you are or you are working with non-accredited and sophisticated investors. 

A property qualifies as Homestead for this exemption if an eligible owner files a Principal Residence Exemption (PRE): https://www.michigan.gov/taxes/0,4676,7-238-43535_43539-210891--,00.html#:~:text=Section%20211.7cc%20and%20211.7,purposes%20up%20to%2018%20mills.Many investors have gotten an ugly surprise when they bought a property that was a primary residence of the seller for the last 20 years.

Preforeclosure, Pre-Probate, tax liens are  OK -- however most seasoned and newbie investors are calling these leads as well and making offers.