these deals are done with your commercial banker .. they are not something that is advertised or talked about.. its why I keep all my accounts and my affiliated companies accounts at my commercial bank. you need to be able to talk to your personal banker and that banker needs to be in a Senior position.. thats how it worked for me.

Should they be made into a small common area that the main unit also has access to?

Can you remember any wraps you've seen in the last month and what business they advertised? 

Makes your property more accessible (at least on the surface).Bad: Has a cost which is not used most of the time.

One of the PMs I use, does some investing on the side and has access to his own set of contractors/vendors.

I hear them advertise these short notes with Connect Invest a lot and that you can start with $500. 

What "is" financially responsible is easily accessible to find, as is the simple math performed above.

I could still access equity through the HELOC for future expansion and the rent would cover HELOC interest payments while I stabilize future assets. 

Someone else already found and advertised the property for you. 

Funds usually don't advertise