You can go on Zillow, Rent-O-Meter, Redfin, Apartments.com, etc. to get a good idea.

This knowledge(not just info on these things) becomes your BS meter. 

Some of our clients have even installed two separate electric meters on the property, which would require two separate addresses.

I went as far as separate electrical meters.

Here are the details:Lower Floor: Already functioning as a separate unit with its own meter, entrance, and bathroom, currently rented to long term tenant who would like to stay, post-sale.Main Floor: Has its own entrance with immediate access to an upstairs.

Where is the difference or is it likely that there is only one meter for utilities so owner would likely have to pay for utilities.

It's called net metering.

Historical expenses will also let you know if there is a significant recurring utility or maintenance bill that that the owner is responsible for: James' video does not mention if the units are individually metered for electricity.

Quote from @John Underwood: This could be ugly for people who own STR's in Hawaii.https://www.sfgate.com/hawaii/article/hawaii-short-term-rental-vacation-bill-19382321.php Once we have our own property with maintenance paid by HOA and location is 4 meters from surfing spot and mortgage is paid by airbnb renter , all financial metrics no longer apply lol

Splitting utilities (getting new meters for gas, electric, and water) is pretty expensive and it's difficult to split the fees accurately between tenants.