Yes, the more you know the more responsible you should be. If you know something isn't right, you should know better than to do it. Everyone should be able to understand feelings and treating people the way you would want to be treated without being taught, but the more you understand, the more you should strive to be better.
I don't believe that people with more knowledge are more ethically responsible. If that was the case then all lawyers would behave ethically and doctors would never get sued for malpractice. I believe that more knowledge gives people the tools to make more ethical decisions, but that doesn't mean they will use it. Plenty of people, including children, make ethical choices everyday without needing any additional information.
Smart people are capable of making poor decisions, and stupid people are fully capable of making generous decisions. A given person's level of knowledge has very little to do with their ability to be ethically responsible. In order to be ethically responsible, someone must be empathetic, understanding, and paitent, which are all independent of how much knowledge they have.
I do not believe people are more ethically responsible if they possess more knowledge. I think it is just as common for people to use that knowledge to bend the rules and change them in their favor. Knowledge does not create ethically responsibility. Some humans are simply self serving and knowledge only makes them more dangerous.
I do not believe that people who are more knowledgeable are more ethically responsible. I think that is always depends on the person. But for somebody to be ethical, they just need to be a good person in nature. I do not think smart people are always going to be more ethical.