Very little risk to the seller with that large of a down payment.

If you have the debt bandwidth, you could potentially take on additional loans and use the equity from the sale as down payments, giving you a tidy little portfolio pretty quickly.

One spouse just got laid off and received a large longevity payment as part of the lay off.

It wouldn't change if I used the $324.70 and went for 138 payments.

At most you have only 14k for down payment with a conventional loan.  

Should I focus my cash towards a down payment or to have the windows replaced, and any other minor repairs?

They are behind in a note payment to me on a residential investment property I sold and financed to them  a few years ago.  

We would then use that 20k as a down payment FHA on a multifamily, house hack one unit, rent out the other three, and rent out the condo.Based on prior estimates from a RE agent, we could rent our condo for anywhere from 1.3k to 1.5k a month. 

That said there is downside if sales do fall, but there is a minimum lease payment in place. 

This implies that the other units will likely be subsidizing your home payment.  4) Purchase of a property in a locale that historically has incredible long-term appreciation.Good luck