Until the business has enough assets to matter, it really doesn't matter all that much.

It's only a matter of time

Look, it matters being happy where you live, it does.

You'll need good contact info for them to be able to collect, and ideally the new address for the tenant however which if you don't have can probably be found easily with some online sleuthing/ contacting their employer, skip tracing software, etc. 

We were fortunate to make a nice little return and their $500 turned into $750 in a matter of 6 months.

So most investors just throw in the same expense factors no matter the age of the property.

If the numbers work, then that's all that matters, though so hard to say for sure.

If there are no boarding house limitation to the number of unrelated persons, does this structuring matter?  

A friend advised me to check reviews online and look for someone local with experience in single-family homes.

They are also looking for code issues and other hazards which hopefully you are compliant with no matter what.