ANSWER - I think the ability to foretell a death is interesting but to me it suggests a developed sense of precognition as opposed to witchcraft. Witchcraft at its simplest level is the channelling of intent and energy toward a specific goal. The ability to know when somebody is about to die is closer to clairvoyance (telling the future). There is an overlap, many witches do have clairvoyant abilities but it isn't part of what defines a witch and it is an ability enjoyed by many people who not practise witchcraft as well.
The second ability is closer to witchcraft as you are deliberately trying to bring about a specific aim by utilising the power of your emotions. This doesn't necessarily make you a witch but it does mean you are starting to have a go at working with energy and intent which is a path that may well lead you toward witchcraft. (I've added a link at the bottom explaining the made a witch/born a witch thing).
In terms of does it make you a bad witch. Probably not. The fact you are experiencing this ability when linked with darker emotions like anger and spite just means that you are finding these negative emotions easier to manipulate. If it was something you continued to work with you would probably find that over time you would find it easier to direct gentler energies. There are people who would tell you that any element of harm makes you a bad witch but in my opinion that isn't true. It makes sense to me for a witch to use both negative and positive energies in her workings. I'd probably suggest that if you do have these abilities it makes good sense to have a go at using them for something more constructive than winning games of pool though!
How do I know I'm a witch?