However, we (my parents and I are the owners) noticed that they are using the HVAC in excess and using what appears to be unnecessary electric (TVs and lights remain on even when not in use and air conditioner is running constantly).

I wish that were the case but it doesn't appear so. 

I've seen other buildings that look just like mine around boston and it appears that the space is being used some way.

If any red flags appear, you can always make your offer contingent upon the property being vacant at closing. 

Instead she texted me the day that she was supposed to take keys and pay that when she had viewed the home at an earlier date it appeared inhabitable.

The security deposit must be returned to tenant after their tenure unless the property has damaged equivalent to the security deposit. 

Wayne below clarifies the situation the broker Ken is just a broker.. the lender it appears is really Lima One.. 

Mistake #6- Believing you can effectively manage a rental remotely when you appear to have no systems or processes in place.

Hello,I found this link to this short term rental calculator: https://www.biggerpockets.com/blog/wp-content/uploads/2021/06/STR-Calculator-V2-Locked-.xlsxIt is very helpful and appears to be a useful evaluation tool. 

Not sure it's better than hiring a coach, but it appears that much of the risk can be mitigated by investing with a turnkey company.