FrameMarket: Category specific page

Hello

How do I tackle these issues?...In order to fetch articles from one specific category and display those on page (created a sub-menu for that) I've created a Category Specific page by copying the "category.php" and gave it a name (category-name.php) before saving it in my theme folder. Now the issues are

a) The articles are appearing on the Category Specific Page list but also appearing on the blogs page list...how do I avoid that duplication? I want that to appear only once.

b) This line of code is fetching thumbnails in the the "Blogs List Page" but not in "Category Specific Page List" <?php the_post_thumbnail('thumbnail',array( 'style'=>'float:left;margin:5px 20px 0px 0px;' ));?>

c) How do I remove this? (please see screenshot)