Having only jira administrators allowed to create projects is limiting. Each department usually has a person that you would like to appoint to manage their group's set of projects and create new ones. If you could setup a new configurable permission set whereby the jira administrators set the following for the user they plan to allow project creator rights:
Administrators will preset the following for each "special" user:
1) Permission scheme - all projects created by the special user will use the assigned permission scheme set by the admin(s).
2) Notification scheme - all projects created by the special user will use the assigned notification scheme set by the admin(s).