Community customizations beyond design/CSS

[luap42]

This post is strongly related to that other one I wrote:

Customization of sites

I think we have consensus for the following: Sites are able to change their color set and header images. Allowing custom css is MVP, however custom js is not. Having extra features that can be enabled/disabled/customized on demand is also something, we would like to have. Help center/FAQ pages need to be customizable too. If no one objects within 48 hours, I’ll write this into the spec-wiki and close this post.

However the difference between these posts is, that this one is about behaviour and the other one is about design. (This is just a clarification, why I think that these posts are not duplicates)