One team leader?

Fully agree - would be a great improvement to have at least 2 team leaders !

notifications: perhaps using the existing ping, or allowing leader to make sub-team ping-able groups from team members, or allowing team member to subscribe to leader notifications, and salute requests for moral support. just popping out angles, maybe one more feasible that others.

+1!

+1
Choose to allow admin rights per member.
Off by default.
Similar to study allow contribution.

Possibly, make it so the forums area near the bottom of the screen has a small arrow under it that you can click to show Team forum posts? (would have a "1" or something next to the arrow if it has messages you haven't looked at?)

+1. I also created a GitHub issue for this topic :-)

+1 for more team leaders/admins

Did anyone notice that this request was implemented?
+1 the Lichess developers!
Team page - settings - team leaders

Thank you lichess mods for your consideration.