Normally the escrow agent will want mutual sign off even if its clear the contract terms indicate one party should be awarded the escrow funds.

Are there specific market indicators or property traits I should be paying attention to?

You cannot rent out an entire home/apartment for fewer than 30 days.Your STR must be registered with the Office of Special Enforcement.

The fact they are complaining online might be an indication the property manager dealt with them properly so be sure to ask the manager for their side of the story.7.

Unless the medical condition meets the state criteria for early termination and that the medical notice does not appear to suggest that, you cannot terminate the lease outright/immediately but that you will begin to market the property for rental and upon securing an acceptable tenant, the lease can be terminated pending a satisfactory property walkthrough indicating no damages. 

You CAN limit that agreement to a specific property; but, as others have stated, agents are looking for a certain amount of loyalty from their clients.If an agent gets vibes from a prospective client that indicates that they want to cheapskate and not pay a professional for their service, they are not likely to waste their time with them.

Quote from @Jesse Valdez: When operating a business, it pays to know the laws.In most states, guests staying fewer than 30 days can be removed by police for failure to pay rent or obey the rules.

Keep your focus on how many crappy properties you can buy each year, instead of buying fewer but better properties.

It may not appear this way on the surface but you are going to come out ahead by focusing on purchasing fewer but quality assets rather than becoming a door accumulator.

Meaning the low hanging fruit for a new investor might be a little higher up on the tree and fewer and farther between.