Ex: tenant daughter (that wasn't on the lease and shouldn't have been residing in the property) broke one of the railing spindles and didn't notify me.

As long as the husband continues to pay rent for a couple more months, I will let the ex off the lease. 

The maintenance/cap ex costs will likely be less these the lower rent class c area.Some things for OP to ponder.  

Significantly more negative when including vacancy, maintenance/cap ex, pm, misc.   

I use 10% for maintenance & cap ex, 8% for vacancy (but not on STR because the estimate from Airdna includes vacancy), 10% for management.

More than likely the asset will in a location where cap ex & management/operational costs are disproportionately higher and therefore your expense ratio will also have to be adjusted to a higher number.  

If each tenant pays you a security deposit (ex. $2,200 and $1,800), couldn't you just put the $4k into a seperate bank of america checking account and not touch it?

For many of us, our cost structure would be higher than yours (vacancy, turnover, maintenance, cap ex) over the long term.

I’m a local Pittsburgh Wholesaler and ex Army Vet.

These are generally specific liens, you can work payoffs with general liens as well, an ex-spouse may accept less for a release and buy their interests.