Hello, I'm happy you've started work at such extension!
Recently I've created the bundle PrivateWikiAccessControl and I think some of the ideas implemented inside could be interesting for you. I can't say it is professional job, because I'm true beginner, but currently it works stable and satisfies our need at our company's private wiki. The main goal was to have the ability to whitelist any page via the Vector Skin interface (with all features at the page, such as Category tree, available). Now the extension/bundle provides the following features:
- Whitelist any page via the Vector skin's menu 'more',
- Whitelist pages by categories,
- Whitelist certain API requests,
- Make all files (images, pdfs, etc.) inaccessible by anonymous , and whitelist certain ones.