Hey Peter,
Firstly I do apologize for the confusions here. There is only 1 settings for this currently in EasySocial and there is no way to handle different redirections based on how the user is logging into the site.
If you want to modify this behavior, the only way is to hack the file that Arlex pointed out above which is to modify the file /components/com_easysocial/views/registration/view.html.php and at line 470 locate the codes below,
$url = FRoute::dashboard(array(), false);
You probably want to change it to,
return $this->redirect('http://www.hakisaki.com/community');