Essentially goals are what you need to define first, then find the strategy that can help you accomplish those.

Mortgage payment is $1,000 on each house, so you're essentially earning $500 per house or $2,000 a month.

All these steps are essential for ensuring that I make an informed decision about whether or not to purchase the property.

Home Warranty (far from perfect, many people don't like them for a lot of reasons mainly because they are a pain to deal with, but as a safety net for someone looking to get going despite not having super deep pockets yet, they are worth looking into IMO, just pick a company with a good track record, and often you can have your agent pay for it as a closing gift). 

My concern is this: essentially the tenant would be paying me under the table for the remaining rent not covered by the voucher.

Everyone essentially says you were a great host so that is your calling card in my opinion.2.

@Cathy MalmroseAll else aside, your son is essentially a landlord for this time and he could put together a lease agreement immediately (ideally with the help of an attorney), which outlines a security deposit in case of damages, requires the prior owner to obtain renters insurance, who pays utilities and any daily rent- especially a daily amount that’s high if they stay beyond a certain date.This would at least cover the primary points in a leaseback.I’m curious about when and how the sellers made the request to stay past closing that your son agreed to - was it just between the two parties or was the Realtor part of that conversation?

Record keeping is essential since profit is what you paid plus what you put in (every receipt counts) subtracted from the sales price . . . . so the better your records are the more you can offset the sales price and the less you pay in taxes but without records, you have no leg to stand on

We improved the property by resurfacing the decks, adding safety railings, painted the outside, fixed the roof, and added a henhouse.

Mortgage payment is $1,000 on each house, so you're essentially earning $500 per house or $2,000 a month.