as promised there is a wiki page  with mostly questions that seem to
be unanswered so far. Some of those questions have already some proposed
answer, but this is still subject of discussion. This was prepared to
move forward since it seems the SCL topic is too complex now.
Let's discuss the topics on Env and Stacks mailing list and vote on
controversial items on some of the next Env and Stacks meeting.
Recommended way to start a discussion:
1) Open up a discussion about a specific topic on the ML (may be one
question or can cover more related questions).
2) add a link to the ML thread into the wiki page , so the discussion
(feel free to add new question to the wiki if not mentioned there yet)