Our site has several thousand product pages and several hundred category pages.

Each page has its own RSS feed, updated whenever the page content changes.

What are best practices for getting all of the feeds published, or at least get them all into circulation?

i.e.

Should I make a single feed that pulls all of the others' content into it to create a gigantic feed just for publishing?

Do I need to publish each feed separately to each different syndication service?

If my sitemaps are already being used, and the feeds are link'd to each page, will the search engine spiders grab my feeds when they hit the pages in the sitemaps?

Thanks for any hints for cutting down on the work involved.