Q2A has great flexibility to change the home page by just changing few lines of configuration in the qa-config.php
For instance , if you want to keep recent activity as your home page then you have to just keep the configuration like this.
'activity' => '',
I have written a detailed blog post on this here - http://q2astore.com/blog/how-to-change-the-home-page-of-q2a-website/
Hope this will be useful for lots of users