(some experts have said to no do that since it leads to other legal issues.)I'm wondering what your experiences have been?

And it's easy to source and document the cash. 

I'm one of the most visible people on the site, so many of the messages come from me.The forms you were offered are a package that we have created with the help of state-specific attorneys so that newer landlords who do need them can have a good set of documents rather than the "free" forms available online that do little to nothing to protect their interests.

I think any of those should be okay but I am not giving legal or accounting advice.I don't see any reason you would need to have a separate LLC and anyone is okay with carrying a note.

I am interested to know which would be the better choice to avoid paying as much taxes and closing costs as legally possible. 

I’m not allowed to legally in my area but everyone does.

And once it reaches 60 days and I haven't gotten paid, is the landlord in his legal right to call a sheriff to evict me?

If so do you ask them to document what they are doing?

You will need a legal partnership contract and your lawyer may suggest what should be included.

If there is a sign some people will not go in to depth about how they pay their Bird dogs legally.