An example of that is tenant must pay for additional electric over flat fee / flat limit since now there is 2 occupants in the home instead of originally one.

Most 3BR turnkey homes are closer to $285K and upwards, so with money more expensive, and minimum rent of $1800... possible break even scenario.

Pro tip--make sure your exhaust fan in the bathroom is vented to the atmosphere--meaning out to the outside.....go out the roof or out the side of the unit or secured to an opening in a soffit vent grille off the house. 

$280k home for $2,500 rent is a personal choice.

I have home owners insurance should i buy another landlords policy as well?

Another property assessment included another home that had been demoed/removed before we bought the property. 

And then the last hurdle is that driving miles between your home and your rental properties by default is considered to be like your "commute" to work, and your commute doesn't count as business miles. 

I've also heard of requirements to own for at least one year before you can use the home as a STR.Hawaii is a leftist state that doesn't protect private property rights.

I told her - the garage door opener is $150 at Home Depot.

If you add unit to your home, your home likely became rent controlled.