Very interesting is the ability to pause the copy of a file or group of files, but I do not see why it should be difficult to make the next steps:
 - Resume in automatic mode the session paused;
 - Only if commanded: persistent suspension;
 - Manually reorder the queue;
 - Maintenance of a group (session) to queue (example: delete a selected item by mistake);
 - Allow the last command data from bypassing the queue (in the case where it is necessary little time for its execution, and to the law of highest priority to the last user operation in progress).

Must not be overloaded by too many simultaneous commands, then:
 - Take into account the latency unit (in cases of conflicting operations) to avoid that most of the time is "spent" in the displacement of the heads etc..;
 - All multiplied by each unit / physical node;
 - Similarly for reading, in synergy with the tail of writing for each unit / node.

Note: I would take in consideration all programs, not just Dolphin. For example: operations controlled by the user simultaneously with a video editing program that reads a movie and creating a new one. Highest priority to the user who will command any different priorities necessity, or reported by the system due to insufficient resources.

Note 2: I've seen similar reports but not very articulate. I hope I have explained what I have in mind.

Reproducible: Always