Based on our observations, they do not prefer young children but can learn to like/tolerate them. Small children (toddlers) should always be supervised with them, and ALL children should be taught how to hold them, be gentle, be patient, etc. before being allowed to play with the dachshunds. Our females are very affectionate to our own children, but not usually to visiting children.
We do not have trouble with this with our dachshunds. We feed them high quality food and, except for the occasional tiny treat, we do not feed them anything else. They have a large yard to play in and are often wrestling and chasing each other. They get plenty of exercise.
Our dachshunds learned all the house rules quickly. Some people say this breed is extra difficult to potty train. Our females were completely house trained in a few months. Our males will mark their territory here and there behind our even though they know better. The key is consistency and rewarding good behavior/discouraging bad behavior. They are very smart and definitely know what we ask of them. If completely undisciplined, they will rarely obey and be stubborn. With a small amount of discipline for disobedience and then a treat when they obey, they are very happy and well-behaved little dogs.
They are incredibly loyal and take being little watchdogs seriously. They will definitely sound the alarm when anyone comes to the door or they hear, smell, or see anything out of the ordinary. However, as far as continuing to bark and not stop even when you want them to stop - they can be trained to learn to calm down sooner rather than later.
Our dachshunds LOVED our terrier as much as they love us. They prefer for everything to always stay the same (they do very well with routine). They tend to be cautious when meeting new people, but if the first meeting goes well, they will run to greet the person the next time they see them. The more socialization the better for these little dogs.
Ours do not. I suggest that it is according to each individual puppy's temperament and also in the way someone greets them. Greeting them calmly or ignoring them for the first few minutes usually completely alleviates the problem if a puppy is prone to it.