For the time, i think it takes the same time to answer a ticket than to quick reply a post.
The tickets can be moved to Support level 2, Administration etc... We also have those things in the forums.
We can also see when someone has replied the post. If you as a costumer need to know what happens with your issue, you can always subscribe your post and you will be emailed when someone replies.
About the ticket id... you can always link your post aswell
A bit longer but it has the same effect.
And about the privacity, one reason why we ask you to link your cPanel to your Forum account is because we can see your details (Contact email, cPanel username, hosting plan) without asking you.