Hi,
Setup is more or less that only I and few guys belong to jira-adminstrator group. All others requiring elevated privileges within projects have project admin roles.
It seems however that you need to belong to jira-adminstrator group in order to configure kanban boards ... It additionally seems that project admin role is not enough for starting and stopping sprints.
Managing sprint permission scheme has been granted to developers so need help to enable project administrators possibility to start and stop sprints and manage kanban boards without letting them to jira-administrator group.
-Jouni