>>94
Morality is relative; there is no good nor bad, just perspective.
Through evolution, we have gained a degree of altruism, which can and is labeled as the source of our morality. This altruism is the reason why we help people and why we are nice to people- so that the help and niceness is reciprocated when we need it. The Golden Rule, basically. However, this is not to say that we have an ingrained sense of right and wrong, a conscience, as we like to call it. Rather we are equipped with these basic principles of altruism so that community and cooperation fostered. Such qualities were crucial back in ancient times when our ancestors fought for survival in their little groups.
Realizing this, no, murder is not bad. Simply, it is just harmful to the group, and anything that is harmful to the group is shunned in place of more productive actions.
To answer some more of your questions (you had quite a few), no, you do not have to adhere to this morality or any other form of morality. Problem is, government and laws and asinine old/dying/dead farts in suits get to decide what you can be punished for.
You are also not obligated to increase the survivability of humanity. We have evolved beyond the point were instinct completely dominates our actions.
I like how you asked so many questions. Don't stop. Question authority. Question everything, and that includes what I have just told you.