There seem to be at least two schools of thought: 1. Don't pet, and he'll remain respectful / fearful, and never challenge you. 2. Raise as pet and train. I did the latter and it has worked out fine, but I'm sure it doesn't always turn out that way. Depends also if you have experience training animals and have the interest and time.
I handled my roo extensively as a chick, but never hand fed, as I never want to be mugged for treats. The moment he became aggressive and pecked my leg at 5 months I was ready with a response that was effective. I had to work with him a few times over a couple of weeks to make the message sink in.
If you search the rooster threads here, you will find specific techniques that work for many roos and people, such as pushing down on the roo's body and neck firmly but gently until they submit, as he would do breeding a hen, carrying him around, stalking, a few moments upside down, etc. I also just spent considerable time in my roo's territory WITHOUT challenging or dominating him, as suggested in a Mother Earth News article. Pick your battles and don't be unnecessarily domineering. My roo knows I am kind and a source of good things. You can search that site for other good articles on handling roos. Once you allow bad behavior to become a habit, your task is much more difficult. If you expect to address bad behavior, wear long pants, closed shoes, long sleeves, gloves... use common sense!
I think defensive aggression is natural and to be expected in a healthy intact male animal whose job is to defend his flock. Chickens are not the smartest yet are surprisingly trainable, and aggression can be averted. On the other hand, other people want or expect any roo they keep to be naturally docile or fearful. Everybody has different expectations and willingness to make an effort/take a risk, and every bird is different.