It is so upsetting to see a situation that you KNOW can be improved, and make EVERYONE much happier. The dog, and the family who will be able to enjoy the dog more. From what you describe, both dogs are being 'set up' for future behavior issues. And both dogs have the ability to 'grow' and become so much more than what they are now. Like a human child, they have potential, they just need someone to guide them as they develop their strengths, and improve on their weaknesses.

For the first situation, I think you are friends with one family member. I wonder if you can ask her to bring her dog and join you in some training sessions. Maybe do the training sessions in HER yard, to make it easier. Even it is only 10 minutes the first few times, it builds a base to work on. Or can you suggest that you both take your dogs to classes? Sounds like your dog does not need more obedience, but what about nose work class, or flyball or Agility introduction? Or as you suggested, the pet therapy training?

Can you ask her and her dog to join you on a walk, and you swap dogs? Since her dog needs some training with leash walking, and you know how to do that, you can work with the dog. And your dog is a polite walker, so she won't have to 'work' at it. You could say you want to talk about x (school, work, sports team, whatever!) and it would be nice to do while walking around. I'm thinking if you get her to spend some time with 'a' dog, hers or yours, she will learn a different way of interacting with 'her' dog. After a few times (not on the first walk!) maybe you can talk about what your goals are in future, parenting and having children, and how working with the dog is good training for that! You have to start with small steps and slowly build and develop what you are aiming toward, with her.

The second one, wow! That man IS nasty and mean! Does he have small children? I worry about them too! Again, can you start with someone your age or younger.

I'll be interested to see what other folks have for ideas for you!