They also offered to pay for the $12 in materials.They also thanked me for taking the time out of my weekend knowing I work out of town.I would rather go there an make sure everything is hooked up properly than have an elderly couple try an do it themselves.

You can keep the rent the same and state the terms are month-to-month, but it should all be in writing and signed by both the landlord and the tenants.Regarding the duties you mentioned: unless the tenant is elderly or handicapped, I leave it to them to (buy) and change light bulbs. 

So a single parent with 3 kids is desirable, but a dual income married couple with two kids and living with elderly parents drawing social security that watch the children while the parents work is undesirable?

The higher 6 digit ones (under 1m but >500k) are the old salt dogs, low enough (<500k) and that's who was doing mortgages via fax machine and telegraph, the tribal elders who travelled by horse and buggy with a top hat.

Importantly, one of the masters should be downstairs to accommodate elderly family members or those with special needs. 

Gifting money may reduce his medicaid, get advice on this... it could be disastrous to not have health insurance if elderly.

The heirs to older investors can loose property in some states as hospitals and old age homes can freeze assets upon the death of an elderly person in an effort to collect debt, leaving a spouse broke.

Could that be because it has a high density of elderly people?

This month I did a rental screening for a sweet elderly couple who got scammed by a sub-to buyer, (who is also a licensed agent, btw) and had no idea they had even sold the home until now, 9 years later, they are going into foreclosure again.  

Assisted Living for the Elderly- Care Home