customize Category archive page

Hi, I'm using Cath Kathmandu Pro, and I would like to customize our "category archive : news" page. This page shows our posts, we use it as a "news" page. Here are my problems in details : 1/ I can't customize the title of this page, and make the border disappear. 2/ I would like to change the widgets of the sidebar (now : archives and "search"), but I don't find where... 3/ How can I show the title of the post above the text 4/ How can I desable the phrases " Posted on XXX by XXX" and "Posted in (category)" Many thanks !