Hello Dirk,
Thanks for writing in!
At the moment, I am seeing post items with a category of Unboxing, Vlog, Youtube, and Miscellaneous. Did you have any custom code that alters the categories in the post meta?
The blog index will not and cannot be edited with the editor. Even using the default WordPress editor, you cannot edit the blog index and the archive pages because it’s contents were dynamically generated by WordPress. You may change the layouts by going to X > Theme Options > Renew > Blog Options and in X > Theme Options > Blog.
Hope this helps.