Your maintenance numbers look very, very light. You're guessing roughly 1.3k per year in maintenance costs...??
This might be enough for regular maintenance (refridgerator going out, recarpeting, repainting, etc.), but have you included the eventual CapEx costs that will slam you for a few k at a time?
-- water heater
-- HVAC
-- roof
I'd guess you're easily closer to 2-3k per year in maintenance/CapEx combined, which makes this a much, much leaner deal.