What Mortals are affected by the first ability?

All Mortals, anywhere in the realm.

If a Mortal with Deathrite dies, who gets the Deathrite ability?

The King's controller, since Deathrite triggers while the units are technically still in the realm.

What happens if a second King of the Realm enters play?

If my opponent plays a Mortal with a Genesis ability and I have a King in play, who gets the Genesis ability?

The player with the King gets the benefit, since they control the Mortal as soon as it's in play.

King of the Realm

Printings