First let me say THANK YOU so much for saving these poor little babies. It sounds like they have had a terrible start in life. You definitely are their guardian angel. The following is just my 2 cents worth.
I think the first thing you need to do is get them to a vet as soon as possible. Don’t worry about them getting comfortable in your home, they may need immediate medical attention. There is always plenty of time to deal with behavior. I believe you want them physically healthy before mental healing can begin.
I’m assuming you have bathed them to get the bugs and dirt off. If Suzie is waddling around it sounds like she may be overweight, OR possible back problems etc. You didn’t say the color of these puppers, are they dapples? This might be the problem with their eyes. Double dapples have problems with their eyes and could possibly be deaf. You describe white spots on their eyes, do you really mean “white spots” or are the eyes opaque looking. If it is opaque, this could very well be cataracts. Since Lucy is young maybe she has juvenile cataracts. Cataracts can be caused by the aging process, injury or heredity. Again they need your vet’s attention.
The behavior is going to be the long haul. This will take lots of time and a great deal of patience. My best suggestion would be to contact a certified pet behaviorist. Ask your vet for advice on whom to contact. Or I have a list by states. Also I don’t know the age of your son, but since you have only had these dogs a short time I would make sure their “together time” is always supervised.
I’m a big fan of Cesar Millan “The Dog Whisperer”. If you have the National Geographic channel, I highly recommend watching his shows. He deals with the psychology of dogs not obedience training. He does have a book titled “Cesar’s Way” which I highly recommend. Another book would be “Dachshund for Dummies”.
I would not let Suzy or Lucy outside unsupervised as they may find a hole in your fence and be gone in the blink of an eye.
This is getting pretty long, so I am going to e-mail you.