When you make a low-ball offer, you might worry about making the seller mad by offering too little and insulting them.

The property taxes are low for California.

You did not include Vacancy reserves, Property Management, and your 3% for both CapEx and Repairs are too low.  

Anyway cap rtes are thrown on here frequently and the way theya re defined on here befuddles me as I am used to the Walgreens / Targets of the world and ( typically A+ tenants in the 5 range A Multi family will get you high 6's low 7's in various markets ) cap rates determine value  eg...

A low fixed rate conventional loan just sits there and pays down quietly, not spurring action. 

During a recession, it's always good to be closer to the low-end than the high-end.

Partner 1: my own Self Direct IRA LLC (out of state LLC, somewhere low cost) Partner 2: my wife's Self Direct IRA LLC (out of state LLC, somewhere low cost) Partner 3: my mother's Self Direct IRA LLC (out of state LLC, somewhere low cost) Partner 4: an LLC that is owned by both my wife and me. 

If you had a million dollars, how would you invest in real estate for ongoing cashflow, diversified portfolio, low-risk, longterm play with minimal hassle?  

The solar has the highest interest rate, but at such a low payment it would be much more beneficial to your financial position to knock out the car payment early if you can because the value of the car is depreciating. 

If your returns are low for other reasons then I'd recommend working on that before venturing into real estate.