Events: Crashes and Terrorist attacks have been discussed in community but no comment from the Devs. As it is they are not very common.
Extra Runway: I don’t get it. Emergency runway?? Runways are costly to build and just reserving a runway for emergencies (which aren’t very common) is a waste of money.
Fire stations are there. But don’t know about EMS.
Different terrain runways?? See the Dev’s answer.
But the game has weather implemented, so snow falls do occur, requiring u to de-ice your runways.