Tenant is a blackjack dealer at a nearby casino, has verifiable income but no landlord refs...has been living with her grandmother.

Not to say there aren't people who are great developers and make money doing it, but I would say it is not the best way to get started in real estate.   15 acres of raw land sounds like a deal for someone who has made plenty of money doing a variety of deals and now wants to go to the casino to take some of those winnings and double down.Only you know your plan.....I think you start with what the city wants to be there. 

Here in Ohio 50 million dollar license fee to start a casino.

The main difference between you and I might be that I'm using a property manager to take care of bed bugs and toilets, which goes against your final point about having better luck at a casino.

A former Structural enginee:  designed airports, casinos, 1M+ sf industrial buildings.

I did enjoy going to all the casinos with all the great poker action.I also enjoy buying 35k properties that I can rent for $800. 

You mentioned this property is near new casino construction.

I know there are casinos, wineries, and agriculture - does this create enough rental demand to ensure there won't be long term vacancies.

She was laid off by Casino she had to get letter from Casino that she would be back to work after the 30 day shut down..

So you can’t just pull out money when you’re at the casino.