I have had several parents ask me if their kid ( son ) could come and help me work on a property.It is a little different now days but generally the  parents know my wife and I very well and want their son to be exposed to construction and real estate.If you can shadow box any expert you will learn tons of information that 20 books would not even touch .Ask your parents for help as to who they know.good luck

Sole member LLC's do not even get the benefit of an exemption from California tax withholding on the sale of property. 

-No debt, (however also no savings whatsoever)-Parents; Low credit scores (have increased from 500 to 620 and eliminated their debt through my planning assistance.

Typically the below are disqualified:Disqualified PersonsThe SDIRA can not be used to fund projects for persons to include: Parents, grandparents, your spouse, your children, your grandchildren, and all of their spousesAdditionally, the disqualified persons can not offer goods, services, or facilities regarding the investment, ie. contractor work, real estate commissions, etc.

Not exactly....a gift amount gets reported but there is no tax, it simply reduces the tax free cap of any future inheritance, at least from parents to children. 

He was living in the parents house after they died .

I’ve been thinking of moving back to my parents but I keep getting mix responses from people.

Sometimes we learn from our parents what NOT to do, and those are great lessons as well.I don't think you need a mentor, I think you have a sharp mind and the necessary drive to figure this out on your own.

Question - has anyone tried house hacking with an parent/in-law or other family member?

My parents did exactly that and as far as I know they just had to show proof of where they got the money from whenever they crossed it over to the US.