They're making a respectable market and trying to acquire the property at the lowest price they can, within reason.

What is the tax treatment with respect to reporting, depreciaiton, etc.

If there is no agreement on price, you can terminate the deal without risking losing your earnest money respectively.

Pay your expenses for each property out of the respective LLC' account; ideally these should be business accounts. 

I always establish this expecation up front, they pay on time and treat my unit right and I address issues in a timely manner and treat them with respect.

And I respect that....I do the same. 

Treat them with respect and be professional.

Could you be more specific with respect to your question? 

Else the tendency to not care and not treat the arrangement with respect, may arise.  

The IRS has provided a safe harbor for certain structural modifications to a building that are not treated as a demolition and thus, not properly chargeable to the capital account with respect to the land on which the building is located.