I read the article about gzip compression and mod_deflate and have two questions.

1) Do I need to add deflate code to my .htaccess file if I enable this option? (I am using Concrete5 as the content management system.)

2) Are there any downsides to using gzip on text/css or application/js files? I note the default mime types under the website optimization option in cpanel are text/html text/plain text/xml.

Thank you.