tomb stone stairwell doesn't work to well because my opponents will get much more value than me
http://gatherer.wizards.com/Pages/Card/ +stairwell
Not necessarily, each player gets the Zombie tokens every upkeep so you can combo out every turn. Mill the active player during their upkeep, then they lose during the draw step. Or if you have the Stairwell out before the Altar, Glacial Chasm can hold the hordes back.