I want to suggest to integrate in ApexD++ the Starbeam File Transfer. This could be a hybrid/integrated client.
The addition would enable encrypted file transfer based on Magnet URI Standard.
The Lib is here: http://spot-on.sf.net
It just needs to run the kernel.exe and add some gui elements to the Apex DC ++ client, ideally Qt.
and a descriptipn how StarBeam works can be found here:
Also chat would be a nice option, as this is as well based on encryption keys. Let´s make the net safer with encrypted traffic and helping to have Apex DC++ this extension.