Sometimes having drains cleaned will get them operational again, but the problem will come back over time. 

If you clean up the park, fix up the junky homes, fix up and rent out the empty homes, and get rid of the bad elements, people will be willing to pay more.  

Not a clean answer but here are some thoughts:One of the best mentors is to get a job working for whoever does what you want to learn. 

You do a mutual lease termination, let her go asap as soon as she can pack and move, the sooner you can advertise and get a new tenant in,the better for your bottom line, give her the deposit back as long as the unit is left in broom clean condition with all personal property removed..

Same with cleaning up between renters etc. 

Since it's a multi-story building with interior hallways, they hired a local cleaning lady.

I'd rather have a nice and clean property.

By October 2016, the condo was mine.Since then, my husband and I have done about $4000 of renovations to the condo (repainted walls and ceiling, refinished the hardwood floor, fixed up and reframed the electric fireplace, crazy amount of cleaning, refinished the sink, put in new blinds, brighter lighting fixtures, etc).  

We will then clean it up a bit and put it on the mls.

If you do choose to do Airbnb it's fairly self managing if you have a reliable cleaning company and handyman.