I will put in my two cents here and I am sure that Jen will respond in the morning.
From the research I did I don't believe that has to be an 'actual' team leader to keep the team running. However, if there are no posts after 190 days Spark may choose to delete the team.
I see no reason why several of you couldn't be co-leaders. One would have to sign up as the actual leader but that's just a case of semantics.
And Sally, as for the schooling - I know that I would be more than willing to help you learn the ropes and I'm sure that Jen would, too. Janet does some of the challenges and if she doesn't have the time we could help with that, too.
Also, when you sign up as a leader or co-leader there is another team that you can be a part of that answers all of those questions. They will automatically send you an invite.
Hope this info is helpful.
Cheryl aka G-Ma
"Walking with a friend in the dark is better than walking alone in the light."
"How does one become a butterfly? You must want to fly so much that you are willing to give up being a caterpillar." ~Trina Paulus