I have a blog in French and in English in their respective categories. The French behaves like I want, but I cannot hide the author's name in big red letters and the top title in the English one. In both the category Blog and in the blog itself I have set hide title and hide author in all the possible places like Item view options, Item view options in category listings, and Category view options, yet no change has occurred, I'm baffled. My site is ecotranslation.org

Any suggestions?

Use the system template to browse these views by adding ?template=system at your URLs (&template... if you are NOT using SEF).

This way you will see your site with the default K2 templates.
If these elements are hidden, then it is a template issue which you should address to the template's developer.