== several things missing when I post a blog entry (“What’s new?”) in BP Groups … The posts don’t show up in “All Posts” on the admin page (I thought I could apply categories there). It almost seems as if they’re not “posts” as far as WP is concerned ==
You’re right. Those are not posts but group activity updates. If you want posts by the group, you could try either:
For WP multisite with BP install – https://wordpress.org/extend/plugins/bp-groupblog/
For single WP or WP multisite with BP install – http://buddydev.com/buddypress/blog-categories-for-groups-plugin/
