405456 Changes to Wordpress Theme

Site is [login to view URL], theme is Magazit from Wobzy. Mainly I selected that because of the "slider" on the homepage. Issue I'm having is that on pages/articles, I'm posting pictures from Flickr and embedded videos from YouTube, which come through fine on the individual article page. On the category and main pages, however, the theme posts an excerpt, which includes a thumbnail of the image. But because neither the images nor the videos are hosted by me, the theme doesn't know what to post. I'm OK potentially hosting the images if there's no way to do a thumbnail of a non-hosted image, but for video the theme probably just has to be changed to accomodate the original size of the embedded video on the category and homepage. I'm fine to potentially even chuck the theme, but I do like the slider.