Yes, your understanding is correct. Specifically:
1. In the included file the RenderTag is instantiated again. It instantiates a NEW RenderTag object. CORRECT?
Yes. Note that this has very little to do with whether there are inclusions, forwards, or anything else. The key concept is that while the JSP specification permits a container to reuse instances of tag-handler implementation classes, the same instance can never be reused while it's currently being called by an invocation. If you had
<a:b>
<a:b/>
</a:b>
in a single page, this would necessitate two different instances of the handler for <a:b>. The situation you're describing is just a more elaborate version of this same situation, as far as tag-handler lifecycles are concerned.
2. But since this included file is a NEW jsp file, it has its own NEW pageContext
Yes, specifically true.
but calling pageContext.getAttribute(section,REQUEST_SCOPE), should retrieve the ORIGINAL section/content pair that I had stored in the outside files pageContext. I believe this is the case, because the included file did get the SAME request object, and the stored section/content pair of values came with it. CORRECT?
Exactly. "Request scope" travels with (and in fact is identical with and implemented in terms of) the ServletRequest object. Request scope is specifically intended for situations where you want data to traverse multiple pages that are all used to respond to a single web request: that is, inclusions and forwards.
Hope that helped, and thanks for the interesting questions!
[ September 24, 2002: Message edited by: Shawn Bayern ]