Otherwise you can find you lose EMD by failing to perform an action. 

Never take any numbers from a seller with much weight, always perform all your own due diligence in order to make a smart move.  

I know there are some Property Management Software out there that have the built in ability to perform tenant screening, but I am a beginning investor that is not looking to invest in an expensive software. 

this is not a service dog. its an emotion support dog. service dogs are trained to perform specific functions. emotional support dogs just exist for companionship, and while they serve medical purposes, are very often fake. you are not allowed to deny this tenant based solely on the animal, but you are allowed to ask for certain verifications. you also, only have to make "reasonable" accommodation to accomodate his "medical device" I imagine you have an argument to evict if the dog is attacking people.

@Sean CarrollIf one flips real estate and performs the work, then it may qualify as a self-employed business which would allow you to open a solo 401k plan.

I would perform a test during due diligence to see if it is working properly, and if it isn't calculate the cost to repair and demand as a credit at closing.Make sure you build in the cost of pumping.  

You want to quickly purchase enough properties that your performing properties help carry your non performing properties.

Should I just let it go, sue the seller for non-performance or transfer my contract to a more patient investor?

I'm focused on MF but have sniffed out some deals that are okay - so long as they have steady performance, I'm good.

Most agents are "Independent Contractors" so to make a long story short, a Broker can tell them "what task to perform"..