There seems to be some lack of knowledge on the owners' part come to think about it.

Hence, your lack of comparisons. 

I don’t know the condition of the property nor how to properly assess it considering my lack of experience – who would I approach due diligence?

The cheapest is not the best, you don't want to lack coverage and be left with a high deductible. 

Finally, the Stessa Cash Management Accounts FAQ page is suspiciously lacking in mention around fees.

I do not appreciate basically being “fired” by my property manager because she was unable to handle firm and constructive feedback regarding the lack of HER communication and multiple mistakes by this company.

I’m sorry to hear about the situation you’re in—it sounds incredibly frustrating, especially when communication from the syndicators has been so lacking.

Zillow was severely lacking and Apartments(dot)com seemed somewhat cumbersome to navigate their CBR, although it at least had good/complete details. 

You should only have to change when your current software has a flaw or lacking feature that is causing you to spend too much work on a work-around.

They're often on the lookout for properties like yours and have the funds but lack real estate connections.