Sorry for the delay, by sheer volume I can't always get to all questions in a timely manner.

With some features you can do this but not with all features because many of them should only be edited in the context of a page (blog for example).

However, the Html content feature you can do this because you can create and edit instances of Html content in Administration> Content Manager and then you can schedule a future publishing date on any page for the instance of Html content.

Hope it helps,

Joe