@paulus1031
Thank you for you help thus far!
I have created a new thread regarding the tag issue.
The most read module has ID number 331, in correlation with 337 and 340.
The faulty category/menu item issue that displayed articles as if all were videos, have been solved. It turned out that all articles needs to be in categories that has a specific menu item pointing to it, otherwise Joomla doesn't understand where it belongs, and apparently randomly chooses something to set as default. I had several menu items pointing to tags instead of categories, and that confused old Joomla.
I am still very interested in knowing if we can remove the author name and publish date from blog view, but keep it in article view, like we could with the tags.