When creating a template for a page you can specify <xen:title>. This will set both the page title and the h1. If you want to set the h1 to something different then you can do <xen:h1> after setting the title and they will both be completely different. You can also set <xen:h1 /> to remove the h1 all together like on the profile page.
I actually would like to have the "Title" which is being sent to users in the "confirmation Email" to be rather short, so literally showing the "domain-name URL" for this "Title".
The "h1" Text should be the same wording as mentioned above (1).
For the "website-Title" (which is usually indexed by Search-Engines) I would like to use a much longer text with some keywords. So for this I would like to use a different text than in (1) and (2) as mentioned above.