Oakleaf,

When you click on the "Forums" tab, you should see all the individual forums and sub-forums in an expanded view -- meaning all the subforums are shown by default. You can collapse each major forum by using the "+" or "up/down arrow" located to the far right of the color bar on each major forum. I believe this is what you are referring to as threaded at the top level? (expand/collapse the heiarchy of forums?)

Sequential at the posts level is controllable in your user profile.

Thx,
Jeff