Hi
Audit can do this. The results may not be too easy to interpret for the read of content at the moment.
You could add audting for getting a reader for content (ie that they made the call to set up the stream to get the content of the file). This will record all access to content everywhere. Restricting the auditing of read of content by paths/id/etc is still to be done. This does not mean they actually pulled all the content, displayed it, understood it, etc.
The audit template for a file would then show who looked up the content and when.
Perhaps you want work flow where you can set a taks for someone to read the doc - it goes in their task list - and at some point they say they have done it.
Regards
Andy