A "what-would-you-do" scenario.

[Jason H.]

Hey BP! A newbie to the forums here and the REI world. Looking forward to learning a great deal from the community...which brings me to my first "what-would-you-do" topic. Would be interested in hearing what you would do in the big picture given all of the following circumstances:

1. Have a personal residence that is rented out to a tenant who paid an entire year up front and will stay longer. The house is on a 30 year fixed conventional at 3.75 with less than a year into the mortgage. What do to with that chunk of change? Just leave it to pay off mortgage each month? Would you and should you somehow use that cash to pay down principal first and use your own salary to pay monthly mortgage payment? Would you create an LLC for this property now that it's rented?
2. Applying for a HELOC: with 20% equity in the residence and considering taking out a line of credit to fund a down payment for an investment property in Chicago, Austin, or Pittsburgh.
3. As a remote investor, you wouldn't be able to travel to those places, but are still interested in those other markets either because you've lived there before or have close contacts on the ground.  What would you invest in turnkey or trust a real estate agent/investor that also has a property management company that does rehabs? 
4. What to do with 1099 income (don't need to it for living expenses) given that I am looking to invest in a property? Would you drop that income into a SDIRA and then use it towards a down payment for a property?

Looking forward to your responses!