#1 seems like a no-brainer, but... My installation changes this setting every time I boot. Since I have a Delta 1010LT, I select ICE1712 (the chipset on the Delta).
I start Jack, then I open the Envy24 control panel for the soundcard, then I open Ardour. The audio in and out of Ardour is adjusted on the Envy 24. There is also a monitor input selector on Envy24. The cables from the Delta 1010LT aren't fully labeled, near as I can tell.
This information is what I have needed at bare minimum to get the editor working. As I can get sound in and out, I'm now at the stage where I'm learning to "edit" on Ardour.