Installation of cable or internet is simply common in every home in America.

Market fluctuations in the stock market take place every day and wild swings are common.

Auto locking access doors for common areas, garages, laundry etc. 

Our thought was to place them in a common back entry way, behind the door.

I have a fourplex in Michigan that has a common room that is set up to serve as a laundry for the 16 total adjacent units. 

Did any problems arise from that?

Truth is, your experience so far is more common than not.

If you consider the grass common area then I would think that it is almost as equivalent to providing lighting in common areas around a multi family where the landlord is responsible for lighting those areas and paying for it.  

You will find that there is no common definition of a turnkey property, and it can be very risky (and expensive) to make any assumptions.The ongoing management of the property is another area of vastly different approaches to turnkey investments.

Single- and two-story homes, joined in pairs by a prefabricated common core (that contains the plumbing and electrical), cluster around a landscaped courtyard.