If you're going under contract, make sure it is required to be delivered vacant of all tenants (and you'd probably save a good amount of time making that known upfront before entering contract negotiations).

As soon as you get their invoice “hand deliver” your payment immediately.4.  

Fact is it costs a lot to deliver a lot.

Biggest driver for vacancy for us is being pet friendly.

They drop off the dirty linens at the laundromat, we pay for their cleaning, and then the laundromat can deliver them once cleaned.

Proper underwriting and due diligence (DD) processes are essential to ensure that projects maintain a strong risk profile while still delivering attractive returns.

If you don't follow the process perfectly (such as by not delivering notice on time, or in the right way, or charging unfairly such as for normal wear and tear) you will be SOL and could even end up having to return the security deposit or even pay them more $ above the security deposit. 

The only mail that could possibly be delivered there is the mail belonging to the previous tenant.

I’m curious, have you noticed any particular renovations or features that have surprised you in terms of the ROI they deliver?

With a month-to-month tenant in place, it should not be too hard to get them out, depending on the state, but you should have written your offer to be delivered vacant if you didn't want to deal with this.