I Need to Make My Addon Domain a Mirror of Primary Domain

My primary website is http://www.mostabear.com, which is active, and I need to create a mirror copy/image of it on my addon domain http://www.mostabear.info.

My intention is to use the .info site to do testing (I’m concerned how WordPress updates will impact my theme) and then I can correct any issues before applying them to my primary website thus protecting my primary website from any downtime. I will need to replicate this process from time to time when planning/doing any major updates/changes to primary website.

I have read all the documentation but am still a bit unclear about the sequence of doing this process….. I use HostGator and have registered my domain names with GoDaddy.

create addon domain (I have registered the name http://www.mostabear.info)
create new database name (mostabear_testing) under the addon domain
copy primary database to addon domain
use search and replace tool on addon domain (siteurl & wp-content.php)
install WordPress to addon domain

Have I missed anything and what order should these processes be done?

I am a novice and am attempting to learn the processes correctly. I must admit to some confusion when reading the documentation while realizing that they are probably written for somewhat more savvy than I.

I have automated backup processes in place i.e. monthly complete and weekly database.