A line of credit does enable you to have cash.

I can grow and still charge less over time because I can have my staff managing more homes with less work which enables my staff to do more proactive things for the owners and tenants and not be swamped with challenges and issues that go with lower income rentals.

In theory, it's a "real estate agent only" subscription-based service that enables real estate brokers to 1) advertise listings, and 2) offer compensation to other agents (for example: the listing broker charges the seller X% commission, and then offers a portion of that commission to a buyer's agent who brings the buyer). 

Doing real estate to enable me to do what is most important to me is incredible. 

Then install a wifi enabled water meter on the water main for each duplex so you can read the two meters from anywhere.   

That enables you to only put 5% down and charge rent to your tenants on the other side.

The points are likely what's enabling the low interest rate.

What is the most financially feasible and potentially lucrative option for me, which would enable me to live in the country part-time and the city part-time?

For example in 2001, as the events of September 11th happened and the world stood still, I was completing a home I had been building for the previous 15 months.Just as the air traffic was frozen, so was the real estate market and, as a result, I couldn’t sell my primary residence which would have enabled us to have the needed down payment to purchase our new home.

I plan on retiring in 10 years in hopes of using rental properties I acquire as my main source of income that will enable me to still hold a W-2 job at my leisure and not because I need it per se.