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

Some get foreclosed others don't but most have issues with making their mortgage payments.

The first purchase you can do with a low down payment of 3.5% through FHA.

Part of me wants to use the HELOC first, then do a refi after construction is completed so I will have access to more equity, then turn that into a down payment for another property.

. - Ask for the cincinnati port authority grant- from whichever lender you use, that grant paid my entire down payment so all I came to the closing table with for a $175k house was $3200 in closing costs - To qualify you must have 700 credit score and not make over $100k.