Any synonyms to the word hate generally have to do with describing the intensity of the feeling, not so much as to how long it lasts. One could assume that the more intense it is the longer it lasts, but this can be, as you've pointed out, unclear.
It is also a stylistic choice to impulsively say "I hate him." (temporarily, becuase he ate my chocolate) or instead the tamer "I'm mad at him." Personally I think "I'm mad at him." is truer to the context for a 'he stole my candy bar' situation, unless the person in general becomes easily enraged over such a thing. Again this is in regards to the person's personality.
If I had to rate words based on intensity it'd go like this (from least intense to most intense):
You could also provide more detail and in writing this is important. There's a difference between "I hate snakes." and "He has a life long hatred of snakes."
To see it in action I recommend this video.