Exactly. Is this really the case, or it just isn't documented? I've send an email to api@ycombinator.com about that and hopefuly, I will be able to shed some light on this, later. I will write as soon as I get a response. (assuming someone responds)
Yep, there are no API methods specifically for getting the Show, Ask, New, Comments etc. lists, yet.
They will probably add such, though.