@Timothy Mackinny You made an absolute very valid point and I got lower rate than this one who I want to deal with at moment but I didn't feel comfortable dealing with them. however the busy builder has no time for my lower cost projects.

Otherwise, I will continue to network on BP.As a quick background of my wife and I -- My wife is an orthopedic nurse practitioner and I am an land manager for an oil & gas company, each with 10 years of experience.  

Do all 4 units have separate gas/electric meters? 

I wouldn't even consider keeping the deposit unless there is valid damage.

Igor Messano thanks for the validation.

Roof, all plumbing, all electric, all HVAC, all gas lines, adding bathroom, moving walls, all windows, huge deck addition, drywall every square inch.

You'll hear people trashing 401K's and the like, because they believe in RE but it's a valid belief to want to be diveresified.

I did not realize until today, Monday August 22, when I checked the documents again, that the seller's "withdrawal" of his offer to sell his property was not actually a valid withdrawal - that in fact I had all day August 19 to accept his counter.It seems clear to me now that the seller was eager to send written notice of withdrawal of his counter offer because he had received a better offer and was chomping at the bit hoping I would not accept by midnight August 19.My question is - is there anything I can do here?

If there is a valid reason such as a family emergency or something of that nature I try not to be a heartless land lord but the truth is late payments are almost always a result of laziness and lack of priorities.  

And looking back, I'm lucky I didn't blow up the block since the gas water heater was in the garage.