The biggest problem currently with ALSA is the .asoundrc file. With a hammerfall it is usually neccesary to set up one, unless you want to use non-interleaved 24 channel audio. This thing is _really_ poorly documented, but if you search on alsa-dev you can find examples that help a bit. I think that most problems come from not setting up the correct audio device for the application using ALSA's conversion library, but instead trying to access the hw directly with some format that the hardware doesn't support.
Another quick fix is to use plughw:0,0 as your devicename in stead of hw:0,0
I think pd will work with any card that can use 'aplay' to playback sound.
Gerard