[brendannz]

Shouldn't we all do like Nietzsche said, to become an overman? To have the will to power, power itself. To have the power to control our surroundings. To throw away our sympathy because that is more harmful than any vice.

Jimi Hendrix (I think) said something about the power of love overcoming the love of power..

I'm not sure if Nietzsche expected every person to become an overman, he just said that the herd, are held back by slave morality, and can't develop their own creative potential... Throw away your sympathies to the point where they're patronising to the other persons growth. It can be insulting to assume the other person is pathetic and weak, and unable to do anything on their own, so you shower them with love and sympathy. As well, all you're seeing is this base creature with no recognition for their potential.. So rather than saying to someone "awww.. you poor pathetic worthless human" and patting them on the back, it may be more useful to question why they're not as awesome as they could be, or empathising with how they feel, because you've felt that way before...

Why? Why do you need to have feelings for others? Why? Doesn't it stop you from greater power? Why? If you have feeling for animals (or human), then how can you heightens your power?

How can you have feelings for others, if you don't know how they are feeling? You can know how other people are feeling by recognising that they have the same needs deep down for love that you have.. and so treat them how they'd like to be treated.

I am willing to kill other people for knowledge. If I were to live in Renaissance period, I will kill people to get detailed information about human anatomies. To create great work of arts.
Yes, nothing satisfy me more than knowledge.

Leonardo Da Vinci did this, although I don't think he murdered anyone. It was questionable from the church in his time... Google Alex Grey, and see his awesome anatomy. He worked in a morgue for many years to develop this understanding for human anatomy. Working in a morgue would be a good suggestion of mine..

How actually do you "love"?
If I were able to love, how will my world look?

I suggest you read Steve Pavlina's article on Soulful Relationships, and Erin Pavlina's article "You are worthy of love." I don't think love is a verb, its more a noun, and expression (of love) is the verb.