As the Dashboard is anoying irritating to change in Confluence, hence Atlassian has an idea that the Layouts can only be changed if the "Default Theme" is selected, I do use another space's Home as the frontpage (e.g. Dashboard)
Unfortunatly, even though the Page are assigned in the Administation > General Configuration:
peeple (users) can still access the /dashboard.action URL, either by a bookmark - or because the Dashboard breadcrum actually points to it.
To always redirect them to the correct Page, I have used the Redirection Plugin and put this in the Site Message:
{redirect:Public:Home}
So as soon as the /dashboard.action Url are loaded, the browser gets redirected to /display/public/Home