You think the editors interact with the system via the REPL? I would assume they just have the edit/delete functionality exposed for every post instead of just their own. Would be interested to know how this is actually implemented.
I believe the source for a subset of HN is available in the Arc distro. I remember PG commenting about having to remove YC specific stuff from there.
YC's application form is integrated with HN. I assume that's the main thing they removed.
He was talking about things like the YC summer/winter application forms, not the moderation system.
Yes, and in fact you can see from that exactly what editors can do. (Look for calls to the function editor.) Editors can basically edit titles, kill stories and ban users.