I'm open for hosting a totally informal BBQ at the house, BYOB and BYO chair too.

As splitting the cash flow a bunch of ways makes no sense, what are some successful strategies people have used to incorporate other investors into your business?

The "business name" is not registered officially or incorporated in any way. 

I'm pushing thirty years old and my background is in corporate finance and valuation.

You already have experience with Flips so just incorporate that into your strategy.  

Is it even possible to make a very low MAO with the cost of flood repairs incorporated (while the owners have insurance money on the way)?

Depending on the area, the rent is basically the same once you incorporate all the expensesC.

Then play musical chairs with them like I used to do credit cards.

One stain looks like red wine where the rocking chair was in the baby's room. 

. :) OP, No, you must file the state requirements for the Articles of Incorporation with your Secretary of State, (An LLC is a corporate entity) you will need the name of the Registered Agent, usually anyone including you.