Is there a way I can duplicate lists and re-edit them?

There's no list copy feature. So only way to do this is navigate to your database, export the userlist row, remove the id, then insert and it'll generate a new id and add the copy to database; now back to CB backend and you should have 2 of the same userlist. A copy feature in various locations is planned for a later release however.

Is there a plugin that helps me treat the list in a layout mode so I can make a landing page of all lists available?

No, but it maybe possible as there's multiple triggers available for CB and that includes for userlists. You could also just link to a Joomla article page and in the article have a link to your userlist. Each userlist can also have its own description when editing the userlist if that's all you're wanting.