Finish HW4

Hi all,
This is my HW4. I deployed my hw4 on Linode. This is my website:  http://inkryan.com/
If someone is interested in my hw4. This is a admin account below. You can try anything you want.
account: admin@gmail.com
password: 12345678

After finishing hw4, I have several questions:
1.In my website. <link href="http://assets02.inkryan.com/assets/logo-artstore-597695d3668f74828b163324824acddf.png" rel="image_src" /> is not work when I shared the website to FB.

2.I set the expires to max on all of my js and css. Could I set the expires to image or other static files?
Are there ant pros and cons to do that?