1. Short of writing an application, this is a manual process.
2. Renaming it seems to be the best option.
3. Every time you check in a file, a new version is created. (This doesn't necessarily mean new revision.) You cannot overwrite a file like Workgroup allows.
4. You can have a serial number tied to a datacard control, set the default value to the new serial number, thus when a new card [file] is created the card will have a new serial number.
thanks Jeff, much as I thought