They are telling you that their fiduciary responsibility is to You, which is a higher standard than that given to just a "customer".  

This would increase my monthly cash flow immensely.

You set the expectation with her that she would have an actual yard and you have failed to meet that standard.

A standard purchase and sale agreement will work. 

As rent increases with inflation, the rest of your numbers will follow.If buying a condo, thoroughly review the financials and make sure reserve account balances are in line with the most recent reserve study.  

Consider, Cost to turn the unit, cost to advertise, down time, and chance next tenant would be any better than this one.I think your late rent issue a few times is small compared to what you could end up with.M2M and let her ride. do rent increase in Spring so your chance of turn will come at better time for you.

It doesnt mean they are making money, what is does mean though is property prices are increasing because of it.

While it's possible that you have different standards for yourself, do you think it any less safe an area?  

So I'm assuming both building A and B are configured to be able to sell as separate units sch as individual meters, kitchen and bathrooms, in other words they meet your areas zoning code standards to be sold separately.

Rents have increased here quite a bit but much less inventory from what I've researched.