Hi Kris,
This kind of functionality really doesn't exist in the Web Gateway at the moment. You've probably seen you can create three different types of system users with either read-write, read-only or administrator access to the system. You have a little bit more flexibility with reporting in that you can create roles you can apply to the different users where you can prefilter any of the reports that they want to look at. But reallly that's all we can currently do. I would say anything new you want to see in the product it's probably worth creating a new idea for on the ideas site below:
http://www.symantec.com/connect/ideas
Hope that helps,
Kevin