Hello!!
To answer your question about contributors, they are here to give suggestions, ideas, and critiques for the group, art, fanfictions ya name it! They also have the ability to watch over the group for any disrespect among members and can take out anything that could be considered inappropriate!
As for what the group is for, its a place where people can free to share their headcanons, pairings, ideas, ocs, and much more! Its ment to make people feel comfortable about sharing these kinda things and feel accepted! That's what has made the Poptropica fandom great for so long, and we wanna keep that acceptance alive and make sure everyone feels as comfortable and welcome as possible!