It would be great if you made it a feature that guests could use the support system (at least create the ticket), as I would like to use the support system for sales inquiries (which is always new people who don't have an account) and it would be good to have the full features of using the different departments rather than the single generic contact us form.

 

Or maybe allow the contact us form to have additional fields such as subject, ability to choose department, etc.

 

I think many other people would also like to use the support desk in this manner.

 

You could even sell support desk as a separate product. I had purchased commerce package just for using the support desk even though I don't use the store part.

With commerce you can, you can setup up the contact us button to act as a support ticket. You'll find the option in AdminCP.