Thanks a lot for responding so quick!

include custom fields (f.e. fields with standard date input) (for things like "if date matches today, then change status to unbreak now")

Partially works, see https://secure.phabricator.com/T655 . Not for dates though, see https://secure.phabricator.com/T6491

Is there a reason why dates are not supported right now? We use it as a core value for our project management and to organize who is doing what on what day.
We only use the "standard" date format the phabricator is offering right now.

A "reminder" feature for urgent tasks and /or an automatic status change if a date reaches a critical point (today, 3 days before deadline, 3 days after deadline...) would be awesome. right now, the date field is only visible in the task detail view, altough this is a very critical and important information for us.
Another idea would be to just diplay the picked date of a task not only in the detail view but also in the "list view" within a workboard. That would also be of great help. This feature seems to be already "in progress", but is not yet ready for shipment, right?

Why would someone create a column called "duplicate" on a workboard, to solve which actual problem which is not "duplicate task status for no good reason"?

The state "duplicate" is only an example for describing the feature I had in mind. You could also think of a card that gets automatically moved to a specific workboard "done", when a status "done" is selected for that task. Or (vice versa) you can think of a task automatically getting a status "done" and getting closed, when the card is moved to a specific workboard "done", f.e. after being finally reviewed and approved by a customer.

Long story short: A function where status and position in a specific workboard are tied together and affect each other.

I hope you understand what I mean. Keep up the amazing work you all do, guys = Phabricator is just awesome overall!

Best regards

Is there a reason why dates are not supported right now?

See the tickets I linked to and/or ask the upstream developers of Phabricator.
The Wikimedia community does not develop Phabricator.

A "reminder" feature for urgent tasks and /or an automatic status change if a date reaches a critical point would be awesome.

See https://phabricator.wikimedia.org/T76094 (for the Wikimedia instance) and https://secure.phabricator.com/T7930 (for Phab in general)

This feature seems to be already "in progress", but is not yet ready for shipment, right?

Without links / references what makes you think so I cannot comment on the probability of any statements.

Long story short: A function where status and position in a specific workboard are tied together and affect each other.

That's https://secure.phabricator.com/T5474

Keep up the amazing work you all do, guys = Phabricator is just awesome overall!

Feel free to tell the upstream maintainers. :)