Restrict search engines from crawling to the root directory by adding the code snippet below to robots.txt file.
If you want to disable access to admin bar for all the users including the administrator, add the following to the functions file.
By default, length of the excerpts in WordPress is 55 words. Tweak the functions by adding the following commands to customize the length so it can fit the layout.
If you were activating a huge plugin and found an error that says memory exhausted just add the following line of code to your wp-config.php file. The above code will increase the memory limit to 64M, but you can change the value to whatever your hosting server is able to support.