Thank you for the love Arjun, I appreciate it ;)
Blindly answering this without seeing what's going on I would recommend the following quickest and straight to the point solutions:
1. Remove Muffin's responsible function to generate the question's description, by opening the qa-theme.php file with your preferred Markdown editor such as Notepad++, and search and erase the following bulk funcion:
// Add question short preview
public function q_list($q_list)
{
// It will contain some code here
}
2. Hide the searchBar on Muffin theme by adding the following CSS line of code below, to Muffin's [custom-styles.css] file:
.header-navbar .qa-search {display: none !important;}
And have the searchBar on the sidebar as you will.
3. As I told you before, you'll have to call MathJax's function on keypress instead of change. Or as I also mentioned before, you can implement MathJax directly on your CKEditor.
Here's a version of CKEditor on my GitHub account with MathJax already included.
Note: I haven't fully tested this yet so create a backup/copy of the CKEditor plugin before pasting this new files. Or just extract the MathJax plugin from this version and make the necessary changes in yours.
This version is plain extracted from: http://ckeditor.com/builder
This is what your new CKEditor should look like: https://jsfiddle.net/1047zxny