But the unsettled regulatory environent may be a concern. 

If you do that you COULD trigger one cause or another with them, but buying with the intent of living at a place as your primary for a period is almost always legit - even if you're not selling your current home. 

my bathroom caused a leak to the unit downstairs.

@Zachary Overstreet The Real Estate Crash of 2008-2010 caused real estate prices to crash across the country - but didn't affect rent amounts.

So I have a co-living insurance policy at replacement cost with rental loss coverage - Steadily only works when its 4 bedrooms or less and they really don't want it (usually causes non-renewals).

Even though you didn’t install the door or cause the issue, the property (and everything in it) became your responsibility the day you closed.

Your property is still a going concern as far as you know it.

Which then causes the milestones or each step to get dragged out due to (way too many people/hands) touching the file.There is a process called ELA or Express Loan approval a buyer can ask for up front. 

Unfortunately, the parents didn’t have a will, and now the adult child is concerned about what to do with the house.

Do you try and force them to get sober, how long does it take before you realize it's a hopeless cause?