Network theme issues

I have got several issues with the Network Theme.

The first is the main page which shows the blog posts with images, despite the posts having images still does not show them - but shows the biking image with "Add an Image to Post"

The second is the search results on the main Network theme (and possibly other pages) do NOT show any results from other blogs in the network - do we need to add a specific plugin to do this?

The third issue is the Image for each post (regardless of default or not) links to the main multisite blog URL and not to the post URL that it is associated.