1. What I suggest is not a "workaround." It is the "as designed" way to add other miscellaneous podcast episodes that are not covered by the automatic sync settings (for the selected podcasts). So, you have your "regular" podcasts that are set to sync automatically, like setting up your DVR to always record your favorite recurring shows. But you have some other random ("one off") episodes you want to include. Throw them on that iPod Podcasts playlist. Keep that iPod Podcasts playlist selected at the bottom of the iPod's Podcasts settings screen. Manually add and remove episodes to that playlist (in your iTunes library). The iPod does not need to be connected. The next time you connect iPod, iTunes syncs whatever podcast episodes it finds there, along with your "regular" podcasts.
What you describe in your original post sounds more like a "workaround." Read what you wrote there and tell me that does not sound likes some "kludge" procedure...
2. This is related to what you describe in your original post...
Apart from the aforementioned problem of an empty device not listing 'podcasts' under 'on my Device
If you use the method I described, you don't have to worry about this "problem" anymore. The Podcasts heading does not appear under On My Device when there are no podcasts on the device. The Audiobooks heading does not appear under On My Device when there are no audiobooks on the device. The TV Shows heading does not appear under On My Device when there are no TV shows on the device. What you describe as a "problem" is how it's designed to work.
the problem of a particular podcast as of just recently not pulling down/updating/refreshing itself with new episodes even when commanded to do so has to be a separate problem restricted to that podcast that should have a separate and logical solution?
I don't have a full understanding of this problem... Are you describing iTunes not "pulling down" new episodes from Apple's servers? Does this problem involve syncing to the iPhone?
3. It's somewhat difficult to understand in words. Any way you can take a screenshot and include in your reply? But if I understand correctly, that list of episodes is shown there to the right (for the selected podcast) because that's what you have stored in your iTunes podcasts library. iTunes shows what is available to sync. If you want to shorten the list, you need to delete those episodes from your podcasts library.