Moving to Tableau Server Administration forums where a answer is more likely to come that will assist with this.

Patrick

For one-time requests just have the requester use Tableau Reader (send them the packaged workbook = .twbx)

For option #2, do you mean a) 3 user Groups per workbook or b) just 3 user Groups that would be used for ALL workbooks?

I would recommend #2b otherwise go with option #1.

I guess I still don't follow the security requirements.  What I recommend is that you try to keep it as simple as possible for the sake of maintaining it.  This also means that you should push-back on any request that requires you create such complex requirements as you don't want to spend your Tableau admin life managing such unreasonable expectations.

Are your reports similar for the various levels of your hierarchies? if they happen to be I would try to implement them with some user filtering.

I had implemented something similar to your hierarchy before.

1. Nation

2. Region (6)

3. District (40+)

4. Publishers

My user started going done the path of a project for each level in the hierarchy. We ended up redesigning the reports to contain user filtering. Which meant less projects and admin on my side and the added bonus was he did not have to support a dashboard for each level in the hierarchy.