I have an instance set up, but as I recall it was not possible to create an "instance" without being part of a "project", and adding me to a project required manual intervention.
Topic on Talk:Wikimedia Labs/Flow
This is the intention. By default you have no access. You must request a project, or ask to be added to a project by a current member. Also, you must be in the sysadmin role to create/delete instances. Someone already in the sysadmin role of a project can add you to the role.
The concept is for Labs to be a community, and for the community to maintain most actions.