Yes, because I really don't know how would you hide all those <link> tags. Those are definitions that tells your browser which files it needs to load in order to present your web site correctly
You could change the template name throughout the site yourself if you wanted to, but you'd need to make sure you replace ALL references to it throughout ALL the files and DB.
You can change the template name if you want but as @CMYKreative told you, you'd need to make sure you replace ALL references to it throughout ALL the files and DB. If you are not familiar with the process you can only do harm so be sure you know what you are doing