Magento Ecommerce

I am looking for magento eCommerce template but have some queries,

After purchasing the magento template license from envato, the template will be related to me or i have to license it again after some duration.
the template previews only the front end of the website, what about the magento admin panel to manage the whole data on the website? Second is the admin panel of magento is customizable as per the user rights etc?