Knights of Tezoth

Does stealth dissipate from any active action other than movement?

Generalissimo
In exchange for 1 AP, changes individual turn order to team turns, whereby the character's team gains the right of first move. Also, in exchange for 1 AP, can grant an ally an additional turn. 

Does this remain active until the end of the battle after activation?

In general, different basic/unique leadership skills cannot be used if the leader has been killed?