We're in our first month of releasing Zammad [1] an open source Zendesk alternative with pretty neat features. You can check out some screenshots or a free 30 day trial oft our hosted solution on our commercial site [2]. I really like your feature ideas and will later create issues for them. Would be great if you add some too if you have more of them.

Full disclosure: I'm part of the maintainer staff.

[1] https://github.com/zammad/zammad/ [2] https://zammad.com