any more tips on this one guys?
You could use the LoginRedirector plugin:
It allows to redirect users to dashboard, profile or a custom page. It can also be configured for a different redirect on the first login after registration. If the plugin is not 100% what you need, I'm sure you can take its code as a starting point at least.
Find the action file (most likely seems to be register)
where the forward is at the bottom change to the following:
forward($vars['url'] . "pg/dashboard");
If you look at Shouvik's post you will also find another answer. Go to root/mod/riverdashboard/index.php
at the top there should be the following:
if so, remove it. Then non-loggedin users can view the dashboard.