Is there a way to open the user admin interface with a specific user/group already loaded, using a specific URL or URL parameters for the user admin UI?

We did not. I haven't had a chance to try it in 6 yet to see if this behavior has changed.

We have a client using out-of-the-box Social Collaboration features for a blog. We've noticed that when using the "Categories" and "Archives" components on a blog entry (e.g. on any page for which com.adobe.cq.social.blog.Blog.isEntry() would return true), the output of those components is blank. Th...

We have a set of components for which we are using editbars rather than rollovers for various UI reasons. On a single page we may have around 40 components with these editbars. In AEM 5.6.1 we are seeing a significant JS performance issue when switching from edit mode to preview mode, as well as a f...