Product Owner and Developer (all Roles) get the Right to manage their Ownerships (adding and removing their membership in a Project)
on the other hand they are not allowed to manage Projects (which leaves Userstories, Acceptance Tests and Tasks)
until there is some kind of Project Manager (read up responsibility of Product Owner) which works on Project and Sprint-level, it makes sense to give Developers and Product Owners these Rights
maybe that's the time to brainstorm about a Roles & Rights matrix in the settings (managable by Admins)
not sure:
Basically, administrational stuff is stuff, that responsible knowing people should use only. (Not that these people can't make mistakes :D )
On the other hand, at the current state it could be useful for a Product Owner to manage their Ownerships.
So, try it out. Worst thing that could happen is deletion of projects. There should be DB-backups anyway.