Tested it and it works here, with Ableton 8 on Windows.
I set the channel in your patch to 1, the output channel in PD to MidiYoke output 1 and I can trigger clips.

If you see Midi coming into Live, but you still cannot trigger clips, check if you have switched on the "remote"-option for the your MidiYoke input.

AFAIK you cannot control the volume of the clips through velocity - if you want to do so, you would have to map this info to a Midi CC.