Very informative, thank you. I've been using KBs for 20 years trained by a top rated instructor i.e. not a 6-week trained PT. They dramatically improved my fitness and strength, which is why people think I'm about 55, when I am 73 next birthday.
My original instructor explained your points, but your explanation is more complete and very educational.
Most people that I have met in 22+ years at the gym hate KBs, which is a pity. They usually tell me how "dangerous" KBs are. I agree with them, and say yes if you've been "taught" in a class by some soul cycle instructor doubling as your PT then they are dangerous. You'll wreck your shoulders, lower back and hamstrings in an instant - and especially if you don’t have any idea of the proper and safe grip.
KBs are fantastic for women. Unfortunately mass instruction in classes has prejudiced their view of the opportunity.