You will also need wall hangings and art, not to mention kitchen stuff like silverware, pots and pans,

For instance, one property seems to have an extra bathroom that is not listed in the county records.I plan to make some modifications, including removing a closet wall to expand a bathroom and taking out a kitchen island that contains electrical outlets and a switch.

The rental might be vacant for a month,(8% loss) or a tenant might not pay for a month while you pay to evict them.(8-16% loss)  A $1,000 appliance/water heater, or a $8k rook or hvac unit might go out.(5-40% loss)  You should be paying a PM 8%.

A cabin that in theory would have cash flowed positive almost $1K/month had the kitchen drain go through the crawl space and dump out about 4' away from the house.

Secondly the kitchen could use some cosmetic upgrades as well especially considering the bathrooms look so nice. 

Roofs, windows, doors, flooring, appliances etc., these things have use spans and as time passes the expenses come home to roost.

To convert the garage into an ADU, you would be adding a kitchen and bathroom.

The occupants steal the appliances, cabinets, doors, toilets, and everything else they can sell.

She found a dead mouse in kitchen.

If the kitchen was not cleaned properly, it certainly should have been.