In terms of how your going to finance your deal, while cash is always easiest and less stressful.

What rights over the property would my fiancé have once the other two have been gifted? 

This is the easiest but longest wayDo you have friends that are interested in real estate that have money but don't have time or knowledge on how to invest?

I've bought a real turnkey property this year and it was the easiest/pain-free transaction ever.

Here are the details:- Mother owns a home in upstate South Carolina- $170k ARV- $58k mortgage balance- The remaining equity is being gifted to me- Approx. $12k in renovations necessary to make rent-ready- Work mostly done and renters expected in by Feb 1, '21 if not soonerOnce the renovations are complete, which should be done before end-of-year, I can purchase the home from my mother; however, it would behoove me to spike my credit score by paying down some personal debt (which I intend to transfer to the equity of this home upon closing) before originating the conventional mortgage on this property. 

We wanted to offer them $1000 gift but a short sale attorney said it would be an arms length violation.

I own 27% of a rental single family home which was acquired in 2016 and now my grandparents are looking to gift the rest of the 73% which they own to me. 

That might be the easiest. 

I'll be using the equity in the soon-to-be-purchased home (which has been gifted to me by my mother) as collateral for the loan as well as signing a personal guarantee (I have a strong W2 & earnings).

But you can work with your accountant to make it part of her lifetime gift exemption.