You do not need to setup Title or Descriptions in termplates in any way. If you enter the title and meta description in the SEO meta area of the page in the admin... BC will automatically render these in your head.
I saw in a previous post that you mentioned that in V3, you cannot change the meta description via the properties button in the text editor (under Manage > Pages). I am having an issue with this too. I need to edit my meta description; however, when i do, the change never shows up. It only shows the initial meta description set for that page. I can't figure out any other way to change that description.