Dear God what have I missed here? I guess this was partly aimed at me as I know you despair of my parenting cod 
What I have done with ds is control his food as completely as I could while he was too young to know any different. I did not give him anything with sugar in - can't see the point personally. He didn't need it or want it. As he has got older he has wanted to try things at people's houses etc. I have let him eat what he wants at parties now he is old enough to choose his own food. He tends to take some of the sugary chocolatey food and try it, but not much gets eaten. He tends to lick it or nibble it and then put it down.
Recently he has enjoyed some home made cakes but he tends to leave the icing. It must just taste a bit too sickly to him. However he is very fond of ice cream and someone bought him a box of nice Italian chocolates for his birthday 
He liked them very much indeed and asked for them several times a day, but now he knows they are all gone he has not mentioned them again.
I am happy for him to eat nice home made type cakes and biscuits etc as a treat occasionally. I sometimes eat them and he will too, or we'll order ice cream in a restaurant or something. I am not happy for him to eat crap confectionary and junk food, and will do what I can to distract him, substitute something else or limit what he has if I can, when those foods are around.
So far this has worked really well and I am very pleased with how it's gone. He adores fruit and seems to have a good natural taste for food. I am sure this will change as he gets older, peer pressure, etc etc. I am slowly letting him take more responsibility for what he eats. However I won't buy junk food to have at home because that is not the way we eat. Yes I do have the odd bag of mini cheddars 
But I generally don't eat that sort of thing. I am sure he will get 'unsuitable' treats at friends' houses that I won't know about. I am not going to have a trauma about it :)
I don't see the perceived problem with controlling their food totally while they are younger, and aiming to keep the level of junk low throughout their lives. I don't know whether this approach will work but it seems to me to be worth trying. I have had many people say to me "Oh when he is older he will just go mad and binge on it." Maybe he will. I can only provide healthy choices now and feel glad that for at least the early years of his life he had mostly excellent healthy food.
I don't expect you wanted such a long and serious answer cod but I have seen this topic come up before and thought it worthwhile trying to explain what my personal approach is.