Hi Yogie -
You CAN add more than 8 customizable feeds, all you have to do is go to your "installed plugins' tab, click "edit" at the Category - RSS widget menu, then look at the "category-rss-widget-menu/rss.php file and scroll down the list, copy the lines that have
$rss_cat_8_name_value = get_option('rss-categ_8_name');
$rss_cat_8_link_value = get_option('rss-categ_8_link');
in them, paste those underneath and change the 8 to 9. You will need to look for 3 sets of this kind of coding. Just keep scrolling down to find them, copy the last set of coding with 8's n them, paste it underneath and change the 8's to 9. Then save your file. Now you will have 9 categories. If you need more, repeat above instructions.
That's about as fancy as I can get with coding, hope this helps. I'm still having trouble figuring out what to put in the "RSS Link" box, can you help me with that? Thanks, Beckybob