And is it necessary?
Are there any 3rd parties that rate apps for security and things of the sort?
When you install a Chrome extension or app, Chrome warns you about the data access required by that item. This is just a general warning, as most of the apps and extensions don't access or even don't need your private data. Some extensions may play with your private data, and we have seen various cases where a particular extension was involved in malicious activities.
Unfortunately, there is no manual review process for the extensions and apps available on Chrome Web Store. Also, no such third-party site is there. Although there are some third-party sources like CNet and Softpedia, which review, rate and host browser extensions along with other Software, I'm not very sure about their review process. Most of these sites steal extensions from Chrome Web Store and other sources, and host on their own servers even without the permission of the developer.
Don't grant access to all your information to an app if you don't trust the extension. If you trust the extension and it's publisher then you can continue adding it. Chrome is very secure and I don't think it gives personal details to any app.