From what I can tell, it would appear that someone tweaked your feeds at one time and then abandoned them. If you rolled back to the WordPress out-of-the-box default, you’d have an excellent and flexible solution. My guess is that even an intermediate WordPress developer could do it in under 20 minutes. My suspicion is that you’ve got a simple plugin that’s causing the wonky behavior right now–removing it would also remove a chunk of custom code and speed up your site at the same time. I’m happy to help if you don’t have someone on staff for these types of changes.