The part of a feature that plugs into the cms page is what we call the feature module. It can link to supporting pages, but it should not be trying to talk to other controls that may or may not exist on the cms page, the feature module should be self contained, it can only be in one content pane of the page you cannot have part of it in one pane and part in another.

You can do layout within your feature module though, so you put it in the center and use the whole width and internal to your feature module you can use whatever markup you like to achieve a column layout within the control. You can build menus any way you like either just as html or by using menu controls that you databind or populate yourself.

There is nothing built in that does what I think you are looking for. Features like WebStore have an admin menu but it is on a separate supporting page not in the feature module and it is just a simple list.

Hope it helps,

Joe