How to elegantly and effectively quote org fragments?

[Alain.Cochard@unistra.fr]

Hello.

So far, the main motivation for me is to be able to insert into an org
file some org fragments found on the Internet, without their
interacting with the org file.

Sorry if these are easy questions -- I did spend time with the manual,
the FAQ, the list archive, and the web.  The best I found is to use an
org SRC block, but I do not find it satisfactory.  Plus I cannot even
have it work properly.

(1) Say I have have this in my org file (star in 1st column):

	* a regular headline: writing org examples 

	  #+BEGIN_SRC org
		,* a headline only for the example
		,** a subheadline
		text
	  #+END_SRC

Is it the best that one can do to quote some org code?  Since I use
(org-startup-indented t), I would expect to have the corresponding
indentation.  Also, if not possible to avoid the escaping commas, I
would like to at least have them for each line, not only for the
headlines.  So I would like something like this:

	* a regular headline: writing org examples 

	  #+BEGIN_SRC org
	   ,* a headline only for the example
	   ,  * a subheadline
	   ,    text
	  #+END_SRC

Is (some of) this at all doable?

(2) Now, if in the org edit buffer I do 'C-c C-d' (org-deadline),
insert a DEADLINE:, and go back to my org file, the block now looks
like:

	  #+BEGIN_SRC org
		,* a headline only for the example
		,** a subheadline
		DEADLINE: <2015-05-21 Thu>
		text
	  #+END_SRC

If I do 'M-x org-agenda RET a', I get the following line in the Org
agenda buffer:

    todo:       Deadline:   a regular headline: writing org examples

Is this normal?  Since the deadline is part of the block, I would
expect no entry in the agenda; I tried to escape the DEADLINE with a
comma, but it does not change anything.  So, is there a way to *quote*
a DEADLINE:, i.e., without having an associated entry in the agenda?

Thank you for your help.

[8.2.10 (8.2.10-40-gc763fa-elpa @
/home/cochard/.emacs.d/elpa/org-20150518/)]
GNU Emacs 24.5.1 (x86_64-redhat-linux-gnu, GTK+ Version 3.14.12) of
2015-04-17 on buildvm-04.phx2.fedoraproject.org