I don't believe that emotions are a bad thing. They reveal what our soul is feeling/believing and can be very powerful for inspiring action. i think it is when the emotions hit the ends of the pendulum that they become unhealthy. When they move into things like Hate and Obsession, I beleive it more like a festered wound. Our emotions are great but they must be processed. When we TRUELY sit with our emotions and FEEL what is there it can usually be easily released (energetically/physically) and the lessons gleaned from them. Usually we don't do that. We don't allow ourselves to truely feel it. We let it fester and create drama out of it by telling as many people as possible, which perpetuates the energy instead of dissolving/resolving. Then eventually it becomes anchored into our etheric bodies and becomes that "tape" that we react from in future situations. Not processing our emotions, IMO, has as its end result a loss of free will. As that stuff gets anchored into our energy bodies and into our subconcious, we tend to then start to make choices from that wounding instead of from the present. Our inner 6 year old chooses whether to trust this guy we are dating instead of the present adult.

Hmm, I am not sure if I directly answered your questions. how do you pin down an emotion, sit with it, meditate...
They are not good or evil in and of themselves, our responses to the emotions are good or evil. Also, they can mirror to us unhealthy beliefs we may secretly be holding.
Healthy or unhealthy anger...defined by how we act based upon them. If we go and kill the guy we hate, unleass they are trying to kill you, it is probably unhealthy. If you go within and realize that your hate for him is really rooted in your hate for that aspect of yourself, and then you work to heal that, then it was healthy anger. Also Anger can be healthy if it inspires you to created needed changes.

Hope thats helpful.

Listen to it. Whatever emotion comes up, listen to it. Keep listening to it. Listen to where it is in your body. Listen to what beliefs it comes from. If you listen it will reveal all its secrets to you.

The point is that in the moment, if an emotion arises the seeds of its creation have already been sown. There is no way to stop it, and to suppress it will only delay the unpleasantness and make it worse. Years of suppressed emotion=dis-ease.

So feel it. There is no right/wrong about emotions. But listen to them as well. Feel them and enquire. Ask yourself "who would I be if I didn't hold onto this emotion? What purpose does it serve?" This being whatever emotions you are holding onto, as well as any beliefs/images/etc. that come up. If it is an unpleasant emotion, like anger or hatred, and you recognize that some part of your consiouscness has manifested it (since this is always the case) you can also answer the question "Who would I be if I didn't hold onto this?" As soon as the "dark" part of your consiousness is recognized as playing no further role, it will fall away and the unpleasant emotion will be no more.

We have the power to let go. Buddha said that attachment is the cause of all suffering, the root cause. Therefore the power to release is the power to be free. With emotions, you must feel them first, then you can release them.