I am going into this venture with a business partner, he is the boots on the ground guy and is networked with all the right people, and I am providing the capital to get things rolling via a HELOC on my first mortgage.

Typically folks will get a high interest loan initially because the property is at a discount and wouldn't fit the criteria for a traditional mortgage (fixer upper, cash only).The refi portion is to place a traditional mortgage on there so that you'll have a manageable monthly payment which rent will cover as well as cash in pocket due to the equity that was present.The goal is to control the property with as little money down as possible while positively cash flowing so I'm not sure if get 2 traditional mortgages accomplishes what you're looking for.

Depending on the project you could be a partial owner of a Multifamily Complex controlling 200+ units in the sunbelt with a small investment.

Question 3: Is the longer term solution for the theoretical LLC that I control to own multiple assets, in which case they and their cash flow would be considered by mortgage lenders for future mortgages?

That's usually the best way from the beginning to keep everything under control.

I never intend to evict, but it is the last recourse you have as a housing provider and if the tenants know you won't actually follow through then you will never be in control again. 

I took control of my life and told myself I will only focus on those things which "TRULY" bring me happiness.

The newer ones continually have repair issues, mostly driven the electronic controls and complex systems to squeeze out efficiency. 

If you want to raise some $ and do joint ventures, track record and experience mean way more, but a degree adds, but doesn't subtract. 

But these people usually lose their shirts.The rehab-to-rent model is pretty much dead in western Pennsylvania, especially in C-class, unless you can control rehab costs mercilessly.