IMHO, in a scale of value from 1 - 10:
1. Ticket can be created either by mail/ browser
10
2. Ticket can be assigned to some group mail/personal mail.
7 (to a group or more then an agent is not easy for me to manage, responsible/owner some times is not enought)
3. Ticket can be tracked ,SLAs can be monitored
10
4. Mail should come when someone responds the ticet.
10
5. Reports should be available.
6 (lack in some features in native mode and is not really easy some time to have what you really want)
6. Customer can do attachment and select priorities.
10
7. Customers should be created such that different products can be assigned to him for ticket generation for that product
na (not understand or not used)
8. Customer can view/get notification on receiving ticket/change of status- NOT ALL But some notifications
8 (or all or nothing or with notification (event) but with hard work ;) )