And the tenants still lived there, they had just been putting old mattresses, broken furniture, and crud there for years.

I don't know your living situation but if your paying x,xxx for rent or a mortgage and instead by living in one side and renting out the other you will be paying y,yyy instead and y is less then x that's great, especially if you can rent out your primary residence and make income there too. 

Seems odd as this would be a business expense for my business.  

Lived in The Woodlands for almost 19 years now and been investing up in this area for the last 9.

Once you take over a property as an owner occupant, if it is a single family or condo you can live in it for 1 year and that automatically exempts your unit from rent control.

If I were you I’d look for a subset of a more expensive market.

OK, good luck with that if you have easily accessible assets like a home you don't live in.Meanwhile, what are the odds a term life insurance policy pays out? 

I live in California, this is a bay area property.were not looking to move out of state and house hacking is less palatable when a duplex costs 1.6 million.

If your property management company is good and has built an internal maintenance team which has set rates and had strong relationship relationships with licensed contractor which should keep costs in control, you should never need to shop contractors on your own I wouldn't think.So in short, our policy is give us your preferred contractors upfront if you have them, but then we work all tickets to resolution including dispatch, and payment of invoices.This is of course for operational expenses.  

Or enter "for repairs" and take photographs of expensive new stuff for court...but they may be paying down credit cards.