You can use HTML and javascript at A. Theme Options -> Post Info Items
Is Share this javascript? Then you could just insert it "as is" at Post Info Items. If it requires a PHP snippet, you could add it in index.php line 188, change
PHP Code:
if ( is_home() ) { echo postinfo("$bfa_ata_post_footer_home"); }
to
PHP Code:
if ( is_home() ) { echo postinfo("$bfa_ata_post_footer_home"); SHARE_THIS_CODE(); }
to add it to the footer of posts on the home page. See the next few lines to add it to the other page types in the same way.
As for the icons. See Post Info Items on how to use your own images in the post footer. Copy those icons from /[theme-folder]/images/ to /[theme-folder]/images/icons/ and they will appear at Post Info Items, with instructions on how to include them. Use %comments-rss('linktext')%
to include the comments RSS for each post. Use straight HTML to include links to the RSS feed and the Feedburner link. Look into the source code in your browser to figure out those two links at the top right of the page. Although I am not sure whether it is useful to include the same links (main RSS & Feedburner) into each post.