Last year I adopted the Profit First System (Mike Michalowicz) and use the following accounts to manage my business: Operating Expense, Bonus money, Owners Compensation, Tax, and Vacancy/CAPX/Repairs.

It's better to have a separate system.

Like anything in life- some guests are fantastic people and renew my faith in the STR system as well as humanity, some seem like they are from another planet and have insane expectations.

.), fencing and security systems, and numerous other factors. 

They have systems in place to handle problems quickly before they snowball and run up the costs.

I'd say that over 60% of the time, the "automated underwriting system" (AUS) only calls for one year of tax returns for self employed persons.

The company (which has networks and systems in place to find the best props and rehab to a high standard quickly etc) does all that legwork on their dime and on their time (ie no vacancy risk to you during rehab).

No way you can structure a business plan, go over a system, and create a list of action items needed to accomplish your goal.

If they have kids in the school system, consider extending their lease as month-to-month and terminating between July-August so they have time to move and set their kids up at another school district. 

My concern for you would be exactly that - building it so big that it does turn into a monster you can't manage or grow, because the business systems aren't set up optimally.