It is absolutely vital I have AT LEAST first months rent to cover the majority of the mortgage while I fix up the other unit.

Changing to a 15 year loan would mean your grandma has ~$100 more each month to put toward bills, which can be helpful if she's retired and on a fixed income.

If fixing the house is more expensive than just demoing and redoing it.THat is the simple answer.However you also need to take into account that even if redoing it is (slightly ) more expensive than just fixing said sheetrock... know that a full gut, will result you in a brand new house interior... something that fixing and patching will never even come close to.

That will let you know what really needs fixing up front and what can be deferred.

Equity loans have fixed rates, lines of credit have variable rates, they have no where to go but up. 

I'm willing to go bird-dogging, fix your coffee, whatever it takes to become successful in this business.

You will have your brother on site, find him a good handyman to be your go to guy to fix things and you just might have a winning combination.  

 Not to beat a dead horse but I’ve had some replies to my former discussion, which indicates to me that in my quest to find my first flip property, not counting the last two houses over the last 4 1/2 years that I have successfully turned over for a profit using 2 30-year conventional loans, I can actually purchase a property using my S Corp.The only problem is,  I would need to live in the property that I am fixing up, as I currently do not have a permanent home-base.

I’ve been practicing doing analysis on properties from the mls for fix and hold rental SFH.

There are a number of purchase/sale/holding costs to look out for, that I compiled into this post here: https://www.biggerpockets.com/blogs/8814/70530-fix-and-flip-project-costs-purchase-sale-and-holdingI see that you're located in South Dakota, so in addition to those costs you'll also need to contend with the Contractor's Excise Tax, which is a 2% tax imposed on "prime" contractors engaged in "realty improvement projects" in South Dakota.