First thing: in the future, it would really help us help you if you could restrict a support thread to a single issue to keep the ensuing discussion on-topic.
To change the intro image, you need to go to Appearance > Theme Options and scroll to the bottom of the Intro Settings. There you can add the URL to the image, or video, that you want to use instead of the default.
So I went to my Image Library and grabbed this permalink:
I also tried the Shortcode version:
This does get rid of the default image but I only get a ? instead of the image the link goes to. Suggestion?