Either a probation condition or an existing no contact order.   

Can I use any old title company to lookup any existing liens?

Another vote for booking it if it's an existing STR.

Does the existing tenant have a current lease or are they month to month?

I can help you with market rates - You need to make sure you own the rights for that expansion as it could be part of the existing rooftop easement agreement. 

I didn’t know this type of service existed but I paid $475 and the inspector drove 2.5 hours to get to me.

@Dean Klein  Over the years, we have had similar situations with existing tenants. 

@Andre HoustonCash-out Re-Fi on your existing rentals and leverage the bank money. 

I've heard people talk about getting a hard money lender for this strategy, but I'm wondering what alternatives exist.

Many of the cities on your list are in the Southeast, which is perfect if you want to bet on appreciation but not that great if you want a steady cash flow, if your goal is to generate some passive income target the midwest, and stick to solid suburban B areas, don't make the same mistake as many other OOS investors did chasing high double-digit returns in C-D areas, these returns only exist on paper.