Frankly, you can't have that level of control if you want to use the filesystem alone (without actually "owning" the server — that is, having root or sudo access and having the ability to create system users — and that would require a VPS or a dedicated/co-located server). You would need, at the very least, a database to store metatdata for user actions and, in general, it's safer and easier to use a database-driven application. As such, that goes well beyond the "what do I need to enable" kind of question and into application development (or picking an application, like a content management system (CMS) to use). That's not a support issue, and should be moved/re-asked in the Scripts, 3rd Party Apps, and Programming forum
If you start a thread there, please explain clearly what you intend to have happen (what sorts of permissions you'd like to grant/withhold under which conditions, etc.). We can then help you to either choose off-the-shelf software or give you a clear path to develop a custom solution, depending on which is more appropriate for your needs.