Obviously need to check zoning and set up costs etc. 

I looked up some info on Bullhead City but there isn't much about future plans.

I have sold some properties years ago on lease options where the tenant buyers actually exercise their right and purchased the property. ( I was in the deed.)The reason I am concerned to tie another person’s property up  with the lease option is that people can change their mind, as in the seller.  

If you had to use insurance for one rental, that would push the premium up on the whole policy, wouldn't it?

Without it they are not legally required to do that (look up the "blue brochure" https://dopl.idaho.gov/wp-content/uploads/2023/10/irec-Agenc...).

Expenses are going up just as fast as rent anyway.

Many of those properties don't actually produce income due to turnovers, vacancy, maintenance and damages and you're lucky if they appreciate enough to keep up with inflation.

Lowe's just came out with their biggest appliance sale of the year- up to 40% off.

Everyone has a story, don't get caught up in their story.

You may be safe to get non-commercial F/F adding up to 2 ADUs to a duplex even though by rule this does not qualify (in my area I have never heard of this being an issue).