Starting with the Projected stabilized value, I simply subtract my "required" profit, needed repairs, any working capital to cover negative cash flow, etc).  

This rule says that you should take the ARV x 70% and then subtract out any repairs, and if you are wholesaling subtract that fee as well.

I suspect when you subtract those costs your cash flow projection will be ~$350/month. 

If we lose our job, do we expect the bank to subtract principle from our mortgage balance?

I know once you figure debt and expenses you just subtract it from the income.So, if interest rate of this property was 6 percent (theoretical I can't find it) than the remaining debt would be 1556 a month?

Add capital improvements to that (increases your basis) then subtract depreciation (decreases your basis). 

So you take your rent monthly and add by 12(months) to get your yearly rental income then do the same for all your expenses add them up then subtract all your expenses from your rental income amount.

I pay my friends $50 per hour and subtract it from the deposit except for wear and tear.

An appraisal that demonstrates an appraiser can't add and subtract might.

Subtract another 10% in costs you will be losing $30 per month.