The reason is the rent-to-price ratio is good so you can cash flow, and most of the West side doesn’t have a Point of sale inspection which is really annoying.

However, electing partnership or corporate taxation could be seen as a sale, causing unintended tax consequences.

I would suggest taking the route of option 2 or 3, so not only are you saving over 10k in rent per year but the residents help in paying down the debt.

Whatever approach aligns with your goals, I would hook up with a solid team focused on that investment strategy with the experience behind them—no need to pay your dues if someone else has and you can learn from them. 

Securing funding has been challenging, particularly because my business documents reflect low revenue from only one duplex, and I am currently between jobs.I have identified a reasonably priced piece of land and have saved a small portion of the funds from my duplex sale to invest in this venture.

Suppose new companies do not establish operations in your investment city to create replacement jobs with similar pay.

Can you easily pay vendors and contractors online?

The few lenders that offer no seasoning, they typically make you pay for it in high rates / fees.

Meanwhile, I created one LLC and business bank account to pay property tax, mortgage and day-to-day operating cost.

The HELOC is reusable--you can pay it down and run it back up.