You can change your avatar by accessing your profile in the top right-hand corner after logging in, either on the website or the Android and iOS mobile applications.
If you see the "Teams" tab in the ranking screen, you are in a competition where you can join a team in order to have two rankings: one individual, and one team. It is possible to join a team by clicking on the "Teams" tab and choosing the team you wish to join.
It is possible to change your nickname for a private competition in the options tab of the competition concerned (on the website or from the iOS/Android mobile application).
Yes, you need to enter the platform code provided by your company and then you can register within the Scorecast Business app on Android and iOS.