While he may be completely truthful, you don't want to find yourself in a situation where there are dead siblings with living children of their own, or out of town heirs who need notice, etc... 

We both stand to receive fairly hefty inheritances as she is the financial POA for her 91 year old father, and co-executor of the estate with her only sibling. 

If you have a friend, or sibling (not a parent or spouse) who has any kind of sizeable cash in their IRA, they might be willing to give you a private secured loan from their IRA.

Hello, I have ran multiple businesses & have always been waiting till a good chance  to get into real estate investing. Unfortunately  my mom passed a few months & left my brother & I our childhood home we...

Keep pursuing potential heirs (I think I may have one more potential sibling of the deceased to try)3.

I'm considering acting as the bank and lending to a sibling who is buying a house.1) Is the interest I receive taxable as interest income, or can it be considered gifts between family members?

You would neeed a job (income) and maybe a co-signer (parents, sibling?). 

My parents and siblings on the other hand, could care less.  

Long story short my wife’s grandmother passed away 2 years ago and left her home to my wife’s older sibling and aunt.

Hello,My sibling and I are going to acquire a small office building, which will be leased to tenants.My sibling solely provides the capital for acquisition.