Update 3 on Pi3/PD install - Audio interface:
And final step, the audio interface UCA 202 is also working now. Had to make 1 small change to a configuration file to get it working. And I must say all the complaint I had at first about audio glitches and unstable system are gone now, after getting an external audio interface. I can run semi heavy patches made on my Mac on the PI at lowest latency(64) and I have no glitches at all.
So now I have all the hardware I need and it is talking together nicely. Now some steps towards optimisation must be done, but over all it all works, so very happy builder here