Am I able to have different Wordpress themes for my inner pages, so they aren't the same as my homepage?
Wordpress does that really easily. You just need to have different versions of your index template or single template and name them according to the wordpress rules. this page http://codex.wordpress.org/Category_Templates tells you how you can have a different look for each category of post Get familiar with that and you'll see how you can do it for authors etc.