(1) What logo? Banshee has no logo. Anyway, all page templates can be found in the 'views' directory. The main layout is in 'views/includes/layout_site.xslt'.
(2) There is nothing to support about YouTube. It's a whole different website. But, it is possible to include YouTube videos in a page. Just add the right tags to the page view. Embedding Flash is perfectly possible.