There is an object "get/make-audio-dialog" which outputs/sets device numbers and all other parameters of the audio-dialog window within a patch.

Is there a way to get the list of device names, or as an alternative, a message to send to PD to open the Audio window from within the patch window?

Check out the new mediasettings library in Pd-0.43-extended.

Great - found it. Thanks.

Has anyone had trouble with this library on start-up? The objects won't create until after I've brought up a help-browser file.

Use [import mediasettings] to load the library first. Then they should instantiate just fine.