My brief philosophy on hedonism and moral values

And we're going in circles. Pleasure and suffering are too broad of terms. They can refer to physical or mental states. Probably better to start off with physical states, because then we could apply some reasoning to animals. I don't actually have an ultimate answer to this, so I'm not going to go too deep here. My point for you is that you start with good=pleasure as if that is as deep as you need to go. Your arguments are then shallow since you don't consider things like long term satisfaction. I would start somewhere like, everything thing does exist has some right to exist. If you are going to argue to ending something's existence, you need to make the argument. Things like "I need to eat to exist" are on the one hand simple, but can have some very non-simple aspects.
We weep for that which was once our delight. Kahlil Gibran
When you are joyous, look deep into your heart and you shall find it is only that which has given you sorrow that is giving you joy. When you are sorrowful look again in your heart, and you shall see that in truth you are weeping for that which has been your delight. Khalil Gibran