1- Yes, it is possible to white label. However, I would like to know more about your type of solution so we can offer the best possible options. Please PM me your project objectives.
2 - In Cayenne, right now we don’t have that options where multiple users can work on 1 account. You can share your dashboard, but the permission levels are only skin deep. So not much another user can change.
3 - Right now, Cayenne is free for prototyping. We hope to keep it that way for the foreseeable future. With so many changes and updates we have planned, we can’t guarantee uptime, data retention, etc, We are working on bringing a paid version that can be used in a production environment. Please PM me with your specific requirements, we do have some options available that may be of your interest.