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

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

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?  

You can do residential, but its a ton of work and no matter what, there is tons of competition.

When you see the property, you'll inevitably be influenced by your own taste when, in reality, what matters is first and foremost the the profitability of your investment.

If the same people are involved, it doesn't matter.

No matter where you choose to invest, please keep in mind the following (copy & paste):--------------------------------------------------------------------------------------Recommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a Class A property in Class D area, what quality of tenant will you get?

No matter what strategy you pick, sacrifice is required.

My state is relatively inexpensive in these matters and charges $102 annually for an “Annual Report” which is nothing more than paying to verify your contact information annually.