I believe hate is incredibly overused and that it has been watered down but I do indeed believe that true hate can in someone's heart or what have you. There are people out there who in fact DO hate their parents and would take joy in ending them or seeing them fail miserably at life or anything else to that extreme. But these are extremes.
Personally I believe that there are levels of hate. There can be extreme raw hatred where you'd be likely to murder or person or even resent their existence and there is the subtle hatred of just not enjoying the presence of someone. It's similar to love in a sense, there are levels of love, (imo) like you love your family, or your significant other, or the stranger who needed help with their groceries or a homeless man who just needed a bite to eat, sure its not romantic or what have you but its an act of kindness that you did for their benefit instead of your own. It kind of depends on your definition of love or hate or any emotion. I know people may not agree with my opinion, I've been told many times before, but that's how I see it.
Belittling someone is an act of hatred, stealing from someone is an act of hatred, killing someone etc etc. "Hating" veggies? Well I doubt you would go on a personal vendetta against vegetables unless they've been through a heinous experience regarding them but then you'd have to think do they hate veggies or do they really hate the fact that they were put through that experience and just direct that hatred towards an object, in this case veggies. Idk its all really complicated. Personally I believe you can not want someone to die but you can still very much hate them by wishing misfortune or just not caring what happens to them. I'm not really sure I'm articulating myself right here. Oh well.