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.  

You will get down payment offered and monthly mortgage payments that this buyer would typically be paying a lender.

Your handyman is probably working under a standard business license, which forbids being paid or accepting payment for more than $1000 on any job or for any customer in a given year.

Does anyone look at how long it takes to make your money back on your initial investment (down payment)?  

At the very, very, VERY least ask yourself why someone hasn't paid $14K for that home yet...Most investors are looking at more than that for a down payment so there must be more to the story on why it hasn't sold.  

If by commercial real estate you mean purchasing rental properties, you could probably find a property being sold by the owner, or another investor, and work out a seller financing deal with them where you put 20% down, and make payments each month.

(Assign, double close, quit claim..w.e your preference lol) stack your cash ...take it the next step ( Or if you've a silver tongue use OPM..other peoples money..give em 6% on their money in interest only payments).... ..fix and flip.. same steps except this time guess what?

That's unsecured loans and not applicable to mortgages to be used as a down payment. 

I have a property deal in which the sellers are a year behind on payments and owe the bank $25K to catch up payments.