Hi, It will never cost him the account, think logical The only thing Adsense team can do is to ban this blog.
Your site can get a higher ctr. Use the largest rectangular ad block. (336x some other number. i can't remember) Place these above and below your articles. Lower your bounce rate by using a white background color or by redesigning your blog. Make sure for your ad that their link titles are a natural blue Your text color black and the URL color almost goes unnoticeable. That should help!