If corn is being used as a carb I wouldn't use it as the make or break it ingredient myself. However I do have a dog here with a pretty bad intolerance( not allergy) to it so its just far easier to not have it in any of the foods.
Thing is, most dogfoods use corn more as a protien source which keeps production costs of their food lower. This is the foods i would definately avoid.
Another thing people need to consider is the protien levels in some of the "high quality" kibbles and the damage high protien can do over time. Its far more than just avoiding ingredients, its finding what works for you and what you are comfortable feeding after knowing as much about it as possible.
Welcome to the board, look forward to seeing pictures