RSS feeders allow me to put code on my site that makes headlines /story beginnings appear on my site, with content determined by my choice of site feed and their updates. Right?
I'm not sure what you mean by "RSS feeders".
are usually desktop applications similar to a mail reader, or a newsgroup reader.
RSS feeds are the source of the syndicated data.
I can create orphan pages (I assume that means pages on my site that aren't accessible to the public due to them not having a link from the home/index page) with RSS Feeds. Right?
Orphan pages are pages that aren't linked to from elsewhere (usually not linked to elsewhere on the same site).
They won't do much for SEO, if that's what you are thinking. But yes, you could put an RSS feed on them.
In creating these pages, the RSS feed which was chosen for both its high rank for keywords and content similar to my sites subject matter (such as Cnet Business section) I am creating a link FROM Cnet to my site. Right?
No, you would be linking to them. They would not be linking to you.
And the RSS feeds have little SEO value as the data is all over the web, and downgraded by search engines because of the duplications.
Does it show up as a link when search engines see it?
It will show up as a link from you to them. As far as SEO is concerned it would probably take a bit of pagerank from your site, and it would not contribute anything but content.
In order to create more links to my site, would it be proper to assume that I could create 10 pages on my site that no one publicly can access with 10 different RSS feeds (using content/keyword/rank matches mentioned above)?
If RSS Feeds create links recognized by search engines, is it better to do so as described with orphan pages, or would one benefit more by using subdomains? Or, should you use different domain names for each to make a noticeable difference?
RSS is a protocol
(kinda like HTML), it won't help you with search engines in the way that you are thinking it will.
For what you are envisioning, you'd be better off making your own feed, and getting others to use it (and link back to you in the process).