If you use one of the containers that have header tags around the content title, but don't enter any content for the title, you will end up with < h1 > < /h1 > in the source code.
if you do not wish to use the container titles then use the transparent container.
In terms of SEO it will not make any difference whether you add the title into the container or into your main content, as long as you add header tags around your titles the search engines will not notice any difference.
If you use the container with the header tags (which is what I do) - you should still use header tags in the content for any further titles.
Basically any text which is a title should have a header tag around it, whether it is a h1, h2, h3, h4, h5, or h6.
have a read of this:
Semantic Code and Header Tags in DotNetNuke Skins