These two Deeds have two effects. The first is specifically usable only when the character with them is the team leader. The second function (activating and benefiting from other Chapters' Defensive Stances or Attack Patterns for increased Cohesion cost) doesn't necessarily seem to be limited to only when the character is the team leader. Is this correct, or are these deeds useless when the character with them is not the team leader?

I'd assume that you have to be the leader. The 'also' is a continuance, which would indicate a continuance of conditions. That's the way it'd go down in contract law, anyway!