For me I would ask my PM and Contractor which have earned my trust. 

I only have about 15k in savings and didn't see much improvement over the 10 years and would like to start investing into real estate since its a great way to earn cash on cash return. 

Louis looking to buy a liveable multi-family unit to owner occupy with hopes of dramatically reducing my personal monthly costs.

You have a $55,000 rental and had NET earnings of over $10,000.

What's the standard for paying off the cosigner.. flat fee, a% off the earnings.

While I wait and I want to earn more cash for saving, is there a need for drone/UAS use in the real estate market?

If you can reduce the Heloc payment with own capital etc you increase your cash flow even more, but remember if you are using 100% Heloc you are basically buying this house with none of your own money, so your ROI is infinite.  

And if I didn't have to pay the seller for 5 years, I could earn a lot more money in that period than the money I lost up front by selling the property for a lower amount.Is this possible?

A big part of the advantage of a Roth IRA as I understand it, is that anything earnings on investments are not taxable. 

The last reason is the market is crazy in my area and this particular house had already 5 offers (according to the realtor...) and we would have to offer about 20k over asking to stand a chance, reducing the estimated profit margin to zero.