I had an idea, well 3 actually, were you can lock, unlock and send notifications about your project. For locking, you can search up people's usernames and select them. This means, only the selected people can view the project. Unlocking, were you can change anytime so anybody can view the project. Notifying, when you follow somebody you can notify them, like typing a message, for example:
To: Wooden Swan Project: Moon Bounce!
Message: I need help! Can you help me fix one problem?
People can reply to notifications, and this also unlocks a new feature...
Selected people to edit or fix your projects. Like locking your project, you can select people to help you with your project. If one person hasn't been selected, they will not be able to change it. Although this isn't the same as remixes. Instead of republishing it, you can keep it in your drafts and the fixes or edits you made can be sent privately to the original creator.