MIDI Sculptor
I built a device I call the "Sculptor" for editing MIDI clips in a variety of ways. There's lots of features and several ways of randomizing things. I won't try to explain it all here. You can download it and learn more at https://github.com/adamjmurray/ableton-midi-sculptor
If this is of interest to you, please give it a try and let me know what you think.
Cheers,
Adam