Help desk status'

I am using the Help Desk template.

I really only need 4 status'. Open meaning I need to do something.
Awaiting for Response meaning I'm waiting for the customer
In Process meaning I'm working on it.
Closed meaning it's been completed.

Out of the box, I can't change a ticket to Awaiting for Response or Open, not sure why.

Is there a process where the status can change to Open when my customer makes an entry, and then Awaiting Response when I answer my customer back.

and then have a way to change to In Process ( I assume I could do that now, but havent' tested).

and then my customer should be able to close the ticket.

Alan