More common is you move into bigger, more expensive homes that you buy, or perhaps downsize into a home without a mortgage.

I'll throw in my 2 cents on common differences I've seen in my career:CDFIs - Because of their subsidized financing structure, they have the ability to be a low cost lender (and sometimes provide grants).

If they are on the deed, the property is owned as 'tenants in common'.Is there a tenants in common agreement?

On the OR Coast the regulations have grown 10X in the past 5 years, but there is still significant opportunity, particularly for initial owner/operators. 20%+ CoC is still quite common for premium Coastal STR's. 

For example the license should not only have a cost but also require at least some compliance training targeting some of the most common issues/complaints.

A mortgage lien being the most common one.

Is there a funky property tax issue that arises with the collateral that is a local municipality error and can lender quickly analyze the situation, assess and articulate the risk and allow draws to carry on or will they make the life of the borrower miserable?

While this is not common, its also not uncommon. 

So the major issues in a house are a foundation issue or a structural issue, the next tier down would be a mechanical issue like Electrical, Plumbing, HVAC, then roof - which isn;t an issue a new roof is very common in a fix n flip, and then the outside facade: Brick repair, driveway repair, brick pointing. 

Fortunately - we have a good relationship with our servicers and can get frictional matters that arise rectified/resolved relatively quickly, but the frequency of said matters could certainly be reduced.