Arras Theme Questions

1. How to I add a custom header?

2. Whenever I use the searchbox to search for something on my blog on the top of every post I am having this problem: http://i30.tinypic.com/2qu65ft.jpg

3. The Tweetmeme button is not showing on my blog. It only shows when I view a whole post any reason why? Here’s my blog. http://vh1realitycheck.com/