A 6% investment rate, is a low 5s/high 4s for primary.

It sounds like you are looking to use Traditional IRA money to purchase a rental property?

I have a rental property that used to be our primary residence.

Depending on if this is your primary residence or not can alter the strategy but that's the gist.

A plumber told me that the primary difference between rheem product warranties was the size of anode supplied with the water heater.  

So, it won’t offer you any tax savings on its own.However, one of the primary reasons real estate investors place property into an LLC is for liability protection.

So the heloc difficulty may be because its not a primary home. but im sure you can find a lender for a heloc.have you tried a DSCR because that way you can keep it in your LLC?

Traditional 30-yr mortgage with 20% down.

In RE we traditionally have done brrrr and STRs.  

Gets deeper from there, but that's the high-level.My goals included being work-optional well before the traditional retirement ages tied to retirement accounts, so therefore the places I put my money needed to afford more flexibility.