I think I have touched this in my comment to the first principle. If there is anyone considered as leader, it should be a person open and listening to feedback and also giving feedback. I do not care how many role he/she holds or even if those are well defined. What I need is understanding what is he/she responsible for, be open for communication and how can we help each other.
How can we ensure distributed leadership in small communities? (1-5 people).
Specifically to this point, I do not think small communities up to ~10 people need any defined leadership if they have shared understanding of their own goals and priorities.
How do we ensure leadership roles are accessible and communicated to everyone?
How do we enable group leadership?
Do we have to? I mean, is this a real problem? Are people confused or lost, who is the leader for the area they need help with?