STRs sound like too much work to me.Portfolio income = stock dividends, interest income (from banks, credit union etc), Master Limited Partnerships (Form K-1), Business Development Companies (Form 1099), bonds, interest earned from investing in a real estate debt fund, interest earned from being a private lender

I still need to get more properties by using conventional loans and develop a more stable business credit before doing LLC. 

You will barely notice when things are going well for several months, but when things then go poorly you will be able to think about nothing else!

You can also structure your offer with I know at least a 2% seller credit so that you can be paid at the closing table when you're buying. 

National savings rates have plummeted, increasingly reliant on credit cards to fill financial gaps.

Do you have credit cards with places like Lowes and Home Depot that you can use to buy materials now and not need to pay off for maybe 90 days?

Lowes rewards actually gives us more than a $50 tool rental credit and a flood of emails trying to hype their programs. 

These are large lines of Credit that allow the lender to leverage theirs or investors money into loans..

The investor's theory behind his suggestion was to use the 500k loan to wipe all debt and only pay on the new loan, I'm not sure if this would be advantageous financially due to my current debts monthly payments set at: LTR = 1900MTR = 1500HELOC= 550Vehicle = 850Total = 4800 monthly At current loan rates for 500k, and a 800+ credit score be a lower monthly than the $4800? 

You will make less per transaction and get less credit, but you will understand all the systems and have clients.