Cocoon 3.0 generators/aggregators/calling controllers/include/xslt questions

Hello,

I was trying to find some samples from current C3.0 implementation to know
more
about C3.0 but some information is absent.

Perhaps someone here could answer that:

In some old Cocoon release (2.x) there was a possibility to define
multipart generators, something like:

<map:match="xxx">
  <map:aggregate element="Page">
      <map:part
src="dir/file1.xml"/>                                                    a)
      <map:part
src="dir/file2.xml"/>                                                    b)
      <map:part src="cocoon://call_some_match_generating_XML"/>     c)
      <map:part src="http://somedomain.com/file3.xml"/>
d)
  </map:aggregate>
  ...
</map:match>

1. Is it still possible with C3.0 ? Especially c) option to call some
sitemapservlet ?

2. If i implement my own SAXGenerator can I use it as c) option here ?
(How?):
<map:part type="my-custom"/> ??

3. Is d) valid ?

4. Can i pass additional parameters to c)
like: <map:part src="cocoon://call_some_match_generating_XML?arg=1&arg=2"/>
Are request parameters INHERITED from calling pipeline match ?

5. Can we use simple Java Controller (but NOT rest-controller?) and still
have access
to QueryString Parameters/HTTP Request object within such sitemapservlet ?
What should such a Java class extend or implement? and how does the spring
bean/config for that Controller may look like ?
Will it be still Controller or SAXGenerator ?

6. What is the main difference between include and xinclude (apart from the
fact the
first is cocoon spec? impl while the other is w3c spec impl by cocoon?)
Isn't include cacheable either ?
Can i include/xinclude external src data e.g. src="
http://somedomain.com/file.xml" ?

5. Can I call other REST Controller from REST Controller ?

6. Do XSLT transformations by default have access to ALL QueryString params
with
<xsl:param name="arg1"/>
<xsl:param name="arg2"/>
...
<xsl:param name="argn"/>

without explicitly defining each one in the pipeline as some
{jexl:cocoon.request.param1}?
as map parameters for the XSL transformer ?

Thank you for your time and answers.

We are still hesitating whether to upgrade to Cocoon3.0/Spring or Java EE
stack.

Greetings,
-Greg