If you could manipulate your biochemistry in order not to feel negative emotions ever again, would you?

No, negative emotions are part of what makes us people.

Without them we have a gap in our understanding and our emotional capability...we'd be unable to see the weight of our failures...or even be able to grieve...or even empathise with another person.

No, without them I don't feel like I could operate as a human being...not properly at least.