Can anyone help me understand the costs to getting and maintaining a license? 

I saw 4 properties that didn't look really well maintained and rehabbed in about 2 hours of driving.

Upstairs is well maintained, with all new paint and nice new carpet.

Her husband passed away and she says she cant maintain her house by herself.

I think they could have maintained a decent occupancy/maintenance.  

Depends on the type of property, what other assets you may have, your risk tolerance, the type of tenants, how well the property is maintained and managed, etc. whether you need/want an entity. 

Of course you want to maintain the repairs on the property.

There are also additional costs of operating and maintaining an LLC, like separate bank accounts, annual report filings, tax filings, etc.2.

Short of a perpetual easement, a letter agreement granting permission to the neighbor to install and maintain the fence would negate a future adverse possession claim.

The 6 unit building is cheaper and easier to maintain and does not 'ask for an explanation' from investors.