Also, just remember the NOI does not include debt service which will need to be subtracted to determine cash flow.

Once they meet your Cash Flow criteria, then, subtract the rental income of the unit you will live in to determine your House Hacking Cash Flow.  

Subtract your debt service to get your cash flow.

If you don't know the cap rate, can you do a back of the napkin calculation by adding total rent, back out 10% for vacancy, then subtract 50% for expenses and take the net number and multiply by 10 to get a benchmark on price to offer?

You have to find the value of the house when it is fixed up and subtract the amount you purchased the home for and the amount to fix it up.

That is why the material list is important because it allows you to easily subtract the material cost. 

Since this base amount isn't really defined, would you charge the rental amount that is actually in the lease, or subtract what the average utilities might be and come up with a number?

Subtract the Rehab costs from the ARV.  

You can mentally subtract the rent you would get from the other units you weren't living in to arrive at your final monthly payment amount.

Re-fi lenders will still want a 60-80% LTV but, done right, you'll get your down payment back, if not even more.For cash flow analysis using the rental calculator, I usually assume a 25% down payment and consider it an "expense" that is subtracted from the estimated total monthly rent.