Sort requests based on priority?

Sort requests based on priority?

Hi I cannot work out how do do this.

I need to be able to sort support requests by priority so that High are listed at the top. At the moment I only seem to have options to sort by Request ID, Due Date, Recent Thread, Created Time.  It seems remarkable to me that 'priority' is missing from a support ticket system, or am I missing something?

Also, how can I delete comments made on requests and in accounts?

Thanks

Jason