Hi Stefano, re: tag naming system - the current system is pretty similar to that already, you can assign a name to an object or multiple objects, and then that name will show up in the "Objects" section of the scene browse allowing you to hide/show/lock/unlock/select that object set by the name.

The main request to add to this is hierarchy so I think it will need that whole group and sub-group type of thing.

re:
> Could maybe rely on good ol Windows or Mac file system

I don't think that's feasible since it is many entities within a file that have these properties, not just a whole file. Unless you wanted to require each separate object to reside in its own file but you would end up with a massive quantity of files that way.

- Michael