Your plugin shows some problems:
1. When saving the advanced options there's a PHP Warning in your admin.php file which, in turn, raises an "headers already sent" in the Core's pluggable.php file.
2. Even if you manage to save your options, the main shortcode doesn't output the expected result.
I suggest to check all the values you supply to
foreach loops in admin.php to make sure they are correct values and NOT undefined or null ones.