Is the blog run from the raw IP address? I wrote an article about why you should proxy a blog through a CDN: http://blog.higg.im/2015/02/10/why-i-run-this-blog-on-maxcdn...
I since moved away from roll-you-own WP solutions as it's a devops nightmare, and tricky to get right, unless you pay someone to do it for you.
You should probably try to get your domain off the apex too:
http://blog.higg.im/2014/03/10/getting-jque-re-off-the-apex/