Does this mean that the 480p30 isn't true progressive? That you edit it in the timeline as interlaced?

I read that as an odd way of saying how the image captures progressive frames in a video stream. The true progressive video stream is carried in a 60i signal and then combined to make the correct image.

I read that as an odd way of saying 3:2 or 2:3:3:2 pulldown. The True progressive video stream is carried in a 60i signal, using one of those two techniques.
That sounds reasonable. Do you know if you edit it as interlaced or progressive as far as your timeline settings are concerned (field dominance in other words)?

You edit as progressive. In an editor like Vegas, when you choose field options you get a) upper first, b) lower first, or c) none - progressive.