"So if your vacancy rate is 8%, which is higher than the figures you are quoting... that would be $11,000 annually in rent and $7200 in principal, interest, taxes and insurance. That leaves $3800 per year for maintenance, management fees (which I pay to myself) and plenty of wiggle room if rents decline."

Um...vacancy rate is the market as a whole not your property. Meaning 8% of landlords are bleeding money because they have no rent coming in.