#1- Really? In my years in a day practice, and in my time in the spay/neuter section of the humane society where I work, I have never experienced this.
#3- Did you friend do labwork prior to surgery? Any surgery does carry a risk, of course. I had to sign something saying that I understood I might die when I had my appendectomy done.
Considering the sheer number of intact male dogs that come through our shelter (about 85% of the dogs we have for adoption are males), and the numbers of puppies we will soon see from accidental litters... And accidents can happen to responsible owners. My last dog was from an 'oops' litter at a breeder. She wasn't planning on breeding that female that year, to give the male more time to mature. But the neighbor's working-line and intact cattle dog climbed several very tall fences and got to the mom. The result was 9 puppies. I also took as a surrender 2 years ago an 8 year old chi that was in dystocia from an 'oops', when the owners found an intact male stray chi in the backyard. He'd dug under the fence.
I have also seen far too many females die from pyometras, including a 2 year old pitbull.