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.  

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...).

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

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.

Expenses are going up just as fast as rent anyway.

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). 

Who ultimately has to come up for tbe repair cost is a legal question between you and the neighbor.

If you are willing to do mid-term, you open a lot of boxes up.