Should I use the Apple RSS example file?

Hi!

A few weeks ago I was setting up a podcast for a friend (not even dreaming that I would be a couple of weeks away from using WordPress) and we managed to publish his podcast on iTunes the “Apple way”.
Since RSS and all that crap was unchartered territory to me at the time, downloading Apple’s pdf file example and filling in the blanks seemed like a good way to go. And it worked. It was just an example page to see if we could do it, and we did it. However, has my friend started using the Loudblog engine after that (which takes take of the iTunes tags for you), a few questions remain:

1. What would be the problem in going to the wp-rss file and changing it with the Apple example file? I mean, if the Apple file is correctly filled, if it is based around RSS2 with some add-ons and if it creates a valid RSS feed, then should I be worried about anything else? Any major reason why this couldn’t be done? Just copy the Apple specs, fill in the blanks, and upload it as the wp-rss file?

2. Since I am new to this RSS stuff, I understand that there is a difference between Channel and Item. The Channel being the information about the feed source (your domain, links to the feed file, etc.) and Item being the items/posts themselves. However, when we fill the Apple RSS example file, we have to specificy at least one item (mp3 or AAC item, since we’re talking about podcasting).
Should I just use the latest item post that has an audio enclosure in my site? Should I trust that new items will be automatically added to the feed?
This is a bit confusing for me.
If I specify an item, then I am referring to a specific post. So how come iTunes “knows” when something new has appeared? Are the items automatically added to the RSS file when a new post is created? Or do I have to go to that file and add manually everytime it happens?

This is probably a very ignorant question, I know.
But maybe someone can shed some light on me.

Thank you in advance.

Best regards.