Static CMS: How To Remove 'Written By' 'Comments' and standard menu?

I am trying to adapt a theme for use as a static CMS for a content website. Therefore I want to remove many of the blogging features, which I have been able to do on pages but am struggling to do on posts.

-I have all discussion settings, but there is still a “Leave A Reply” area under every post, how can I get rid of that?
-How can I remove the “WRITTEN BY ___” box under every post?
-How can I remove/replace all sidebar menu elements (SEARCH-NAVIGATION-ARCHIVES-META)? When I go to menus there are many elements grayed out, but I want to remove all of them as they are not relevant to my content.

Any pointers or suggestions would be much appreciated.