You’re only seeing one post because with each iteration of the loop you’re overwriting the previous iteration’s value of $ea_var on the line $ea_var="<article id="post-";. declare $ea_var outside the while loop and change that line to append with .=
One other issue you’ve got is the use of $post->ID won’t work unless you first globalize $post.
I also suggest you use a new instance of WP_Query instead of query_posts, and then just wp_reset_postdata() after the loop, otherwise the shortcode will have unexpected results in some cases.