I'm not sure where you have gotten this information but it doesn't sound right. There's no reason you can't give milk before 1 year, in fact as you wean your child you should introduce milk unless they show signs of intolerance as they need the vitamin D, Calcium, and fat. As for salt children need some salt in their diet, but they should get what they need from natural sources. It's OK to add extra salt for flavor to your children's meals once they start to eat what you eat as long as you keep it moderate.
Peanuts and honey I've heard avoid until they're one year old, then to introduce them one at a time and gradually. The UK gov says 6 months here. Here's another good site for Child nutrition information.
As for why there's confusion the fact is that nobody really knows as there's loads of contradictory information, and "Experts" who compete against each other in how paranoid they can be. My advice is to relax and not let the parenting extremists rule your life. If you limit your child's intake of processed food and encourage your child to eat a balanced diet with a reasonable amount of fruits and vegetables then your child will develop good eating habits that will serve him/her later in life.