The right dog food

Question
I have a 4 year old golden retriever, and we currently feed him a mix of dog food and meats/vegetables. I have a 2 part question:
1) I have been told that dogs can not digest corn which is the lead ingredient in most dog foods. I have been opting for foods that have meat products listed as the lead. Is this correct and what brand do you recommend for this dog?
2) We also add broccoli, carrots, rice apples, bananas and various meats as we have have them for variation and to enhance the taste. He loves them and we feel we are helping his nutrition - are we right to add these items?

P.S. We really work not to overfed him or serve him processed food. Everything is fresh.

Answer
Any of the common brands should be fine.  Most of them have some corn, but it is well down the ingredient list.  It has also been highly processed to where it is quite digestible.  That dogs can't digest corn is part of the standard hype put out be those selling more expensive foods without it.  Straight off the ear, people can't digest corn either and even cows have some trouble with it.  That is why it gets ground and for people and dogs, cooked.  

Take a look at ingredient list of whatever you are feeding.  The ingredients are listed in order of how much there is.  I know dogs do well on the regular Purina which does have corn as the first ingredient.  If you are feeding it, I see no benefit to the dog to change.  You do have to feed a little more of it, but most Goldens would enjoy getting the larger portions.  If corn is on down the list, compare that to what you were told about corn being the lead ingredient in most foods.  There are only a few of the least expensive foods that start with corn.  

If you would feel better about it, and want the smaller firmer stools, you could move up to Pro Plan, Iams, Science Diet, or other similar brands.  All 3 of those are widely used in service dog programs.  Nobody is in a better position to know what is good for dogs or have more incentive to feed good foods.  

All the foods are formulated to be the complete and balanced diet dogs need.  Anything you add, if the dog can digest it, will only upset the careful balance.  No, dogs can't digest raw corn, or most other vegetables.  There is no knowing what they get out of cooked ones, but nothing that they need that isn't already in their dog food.  I would phase out everything else and if you want to, upgrade to a different food.  Make any changes gradually over a week or more.  

I am glad you are trying to avoid over feeding him.  That is far worse than the cheapest food,  http://www.longliveyourdog.com/twoplus/RateYourDog.aspx