You can invest in anything except the following:  Life insurance (SDIRA only) and for both collectables and disqualified parties/prohibited transactions.

Traditional HELOC aren't meant to be transactional, so those transfers need to be done manually which gets very laborious. 

Would it be a beneficial/does it make sense to run the "business" transactions through the LLC (collecting rent, maintenance/repairs, etc)?

Once I pointed how really little it affects my commission they all realized how stupid were there concerns and how little I make, especially all the time I have to put into just one transaction

This transaction not only delivered a solid profit but also showcased the effectiveness of our renovation strategy.

We financed the E Ingram Street deal using our internal capital, ensuring a smooth and expedited transaction.

I'll throw it out there as an option, knowing that no one is really going to take it.Your proposed transaction is low leverage, so very good terms should be available, but FDRs New Deal in the 1930s (which created the kid-friendly home loan ecosystem -- home loans commonly had 10 year balloon payments before that, even if you put 50% down) was only for homes, not for CRE.

We have structured lots of different partnerships this way... but it is always transactional because as others have mentioned, people in relationships for years can still end badly.

However, they don't have a credit history and mentioned they use cash for transactions, offering to pay one year's rent upfront in cash.

Landlords are liable for whomever is in their property and PM are agents thus require the same fiduciary relationship as in any other real estate transaction.