That's the waterer I'm using as well. I did have one chicken struggle to adjust, despite months of training. I ended up using these nipples instead of the ones that come with it:
Rentacoop Nipples
They come with these snap on cups, which both catch the drippings and help the chickens aim...
1. There's something called cord wrap, or cord protector. It's a thick plastic spiral that goes around the cord. I would absolutely use that if your chickens are able to get at the electrical.
2. I have the same thought, so I personally wouldn't hang it.
3. No heat. You have fantastic...