Here is what you are missing, 400k INTEREST ONLY LOAN!!!!
Look, I am considered a contrarian on these boards lately because I have an optimistic view of the future and have put today in perspective of where it falls in the last 20 years. I am not a “real estate is always bad, we are going to hell in a handbasket” guy. And I think you are talking yourself into bad math.
Interest only is nothing more than rent with risk. Use my formula, or at least use the fully amortized piti and ignore the tax deduction, it gets roughly cancelled out by maintenance and upkeep.