In general, it's just a piece of paper that most people wouldn't want to spend the money to sue over later and as most said, much less common on more doors and irrelevant on REO/flips/etc.

If you have enough common space upstairs, I usually leave that reno to the new owner unless the property is in a price range where they all are finished.

Just be aware that it is common for people from up north to fly down south to "check out" properties and the IRS understands this is often just an attempt to expense vacations as business expenses. 

Not common, and not wide-spread."... and a job market that is literally begging for people to work ..." part-time for poverty wages with no benefits."

Is this something folks do commonly? 

They are also known to mismanage money, which can result in huge assessments for common area improvements.

@Ricardo DiazYou are filing your taxes incorrectly if the property is owned as tenants in common and you are reporting 100% of the rental activity.

We’re familiar with the more commonly discussed routes of how to go about doing this, such as:Going to friends and familyCrowdfundingEquity/HELOC/House hackingPrivate moneySubject to/wholesalingPersonal loanRetirement borrowingGrantsBut we’re pretty sure we haven’t thought of everything. 

To your point, 75% leverage doesn’t always work—65% is common.  

The obvious ones are saving them the hassle of listing, and saving them money on agent commission if they choose not to get an agent; but I am sure there are other creative suggestions out there.Is it pretty common for the buyers agent to act as a dual agent in situations like this?