When you analyze a market properly (1% Rules aren't properly), you're analyzing all the properties in that market at the same time.It's even more dangerous for newbies to use any Rule of thumb.Rules of thumb are nothing but shortcuts, which seems to be the growing method of doing anything now. 

STR's, if done right, are viable long term investments meant to cash flow at a reasonable enough level to properly maintain and improve them. 

But they don’t know proper thinning and trimming.  

With a backup plan, and proper (extensive) legal docs, much of the risk can be mitigated.

It takes away your trump card... who wants to evict a sibling? 

I do have one question - I have a partner and we are looking into getting a properly together.

Most inspectors will know that properties only need to meet whatever the code was when they were built, not current code and they usually explain that properly IME.

You might find that installing a mini-split system, properly insulating, and ensuring the finishes match the main home’s quality will make a difference in how the appraiser views it.

Investing in real estate means your money is backed by tangible property....assuming you do it properly.

As @Patrick Drury mentioned- the West Side does not have any POS areas (besides Lakewood, but it's only needed for previously non-owner occupied/rental properties) Something else to consider in Cleveland proper is Lead Safe Testing ..