Currently working on my credit and saving some more but should be ready in a year or less.

I'm looking at purchasing a rental in North Carolina, I have Excellent credit (800+) and money for the down payment..

This is why its best to partner up with an experienced flipper as they will already have that track record to get better terms. 

With your RE LLC, you could seek out a business line of credit to access capital for expanding. 

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

I recommend buying a multi-family, using the DPA, and getting as much credit as you can at closing.

The other important item to consider is keeping your Credit score above 680, this gives you the opportunity to refinance without tax returns into a 30 year fixed rate Rental Loan, or DSCR Loan. 

You could also explore using a home equity line of credit (HELOC) or a cash-out refinance to tap into the $100k equity and use that capital to invest in additional properties, all while keeping the current home as an asset.

Speak to a local lender to see if you can get a line of credit or a loan against it.

Some owners don't keep track of their books very well.