Doors is not an Editor
Doors is intended to be a performance-only tool and has no ability to edit media. Use your favourite Midi/Wav/etc editor to do that.
There is no Streaming Involved
At present, Doors has been to designed 'schedule' media and synchronise the playback nodes using NTP. This has the advantage of eliminating the network as the performance bottleneck, and permits scalability.
However, Input Devices will come later, which do require streaming.
It is not Internet-Ready
At present, Doors is designed for use on a LAN in a single location. Yes, it is technically possible for users and devices to be in different locations. However, such a user will not be able to hear the output of a Part he/she scheduled, if the output device is in a remote location.
In a future version of Doors, the Controller will be able join a group of other Controllers. One location has one Controller, and one Controller has one location. In this case, a Part scheduled on one Controller will also be scheduled on all other Controllers in the group. This permits geographically separate users to collaborate, and for each site to hear all parts of the music. The fidelity of reproduction at any one site depends, of course, upon the quality and number of devices available there.