Hi Mitch,
Could you please try to send some sound into some other channels than the 1 and 2 of your audio card, like [dac~ 3 4]. You said that you could not send any input into PD. Apparently you may not use your sound card at all. The output [dac~] send to channel 1 and 2 of your built-in device which redirect them toward your channel 1 and 2 of your sound card. This is the problem I have, I always thought using my soundcard but this is not the case.
Also, the latest version of PAV18 has changed slightly from 04/10 to the 04/16(latest) and the latest one had the same problem than the older ones according to Phil Burk. Please try to recompile pd with the 04/10 version, that I send to you with another email.
Thanks
Alex