in reply to
When do you step in, and why?
Well I have been on the giving and receiving end of the first two scenarios and I would have felt cheated if any of my very good University friends (they know who they are) had "done it for me" I definatly appreciated every minute of the long hours some of them would sit with me and take me though a problem that I just didn't get. On the other hand when giving help I did find it hard not to rip the keyboard out of peoples hands just to get the problem fixed.
At the other extreme of course I would have no problem tearing the keyboard out of their hands, and I very mutch doubt there would be any objection. There are times for learning and there are times to swallow your pride and get on with it. :-)
---If it doesn't fit use a bigger hammer