How to find out Armed or not, In the air or not. Best way to find out if drone is in the air using mavlink?

Ground Control Software MAVLink
1
  1. Anyway using Mavlink to request for information if the vehicle is armed?
  2. What is the best way to find out if the drone is in the air? (I understood alttitude and relative altitude. But different terrain, the attitude would be different, it would not be accurate to determine altitude if the drone is flying.)