We should all try to practice equanimity. Equanimity means compassion without attachment. If we love our family without any expectations, we will not have expectations and will not get angry. We need to learn to accept what is rather than thinking about what it could be. They say love your kids for who they are and not what you want them to be.
Does anger create negative Karma?
Anger in itself does not create negative Karma. For example, if someone is angry at a situation just keeping it to themselves it does not create bad Karma. It does negatively affect their health for sure. But if our anger is directed towards someone that ends up hurting them, then it certainly creates negative Karma.
Do bad feelings or bad thoughts generate bad Karma?
No. Bad feelings and bad thoughts do not generate bad Karma. It is the action we take based on those thoughts that create bad Karma. With some exceptions for malice and covetousness.
You talked about the degree of suffering changing based on if that person has been helpful in your life. Both people who died suffered the same fate why is it less consequential if the person killed was a stranger?
The person who helped you has done things to make your life easier in some ways. Even then, one commits negative action towards them it has a higher degree of suffering attached to it. Although both a stranger and this person suffered the same fate, it is your actions and your Karma that is important here.
If you are just doing a job for example a soldier is just doing their duty, do they still have to suffer?
Absolutely. The soldier has a choice of whether to commit that negative consequence and by choosing to commit that action, they are creating conditions that will affect them negatively. Now, this is different from imminent danger. For example, if there is someone with a bomb who is about to kill hundreds of people and you kill that person you don’t suffer negative consequences. In this case, you actually saved hundreds of lives.