It's pretty dark as you might expect. Perhaps with a little elevation but not directly from the campground as I recall.

I would say not, or if they are, not particularly noticeable

Organ Pipe Cactus National Monument Well if you get up on a bit of hill you can, about 5-10 miles away

No. Lukeville is 5 miles away.

We did not notice any lights from the border. Very quiet at the campground. Lovely!!

There is a hill between the campground and the city of Sonoyta, just south of the border. You cannot see the city lights from the campground, but it is not a dark sky campground like the ones in Utah. And if you hike up the hill, you can look down on the city lights.

No, actually you are situated up on a bluff so to speak and have a great view to the East. You can hear cars on the highway at times, but never do see Mexico’s night lights.