It's easy, it's clean, it's flexible for all parties to some extent.

The most important thing is they have it neat and clean for you to show and you get it rerented.

As long as you bring in business and run your own investment LLC, and keep yourself clean (you're broker won't like infractions and violations you cause, it's a liability) the broker shouldn't have a problem.

there was something purple on the floors that even after 3 cleanings didn't come out. 

Even if people are knocking down the door to get into your place you will have some vacancy just to account for cleaning/maintenance etc. between tenants, and, if people really are breaking down your door, you're probably not charging enough for rent. 

How much did it cost to clean out?

After 10, my wife would be looking to leave her job as well as we continue to expand.I understand that there will be additional costs in taxes, cleaning fees, and advertising - but is there anything else significant that I am missing?

You find them and simply clean them up a little and do some marketing for a buyer.

I didn't even have to clean! 

Personal life is clean as far as debt is concerned, except for a mortgage.