How to release iPhone from previous owner?

Ok, so I got an iPhone 4 from my boyfriend today; and I called Verizon and tried to activate it, and they said that it was still attached to the previous number, and that I would have to contact those people and yada yada yada. The thing is my boyfriend got it from him mom that he NEVER talks to, and she got it from a friend but neither of us know who… So we have no way to contact them… I need to know if there's some way for me to disconnect that other persons number (they didn't pay for it) and put the iPhone on my line?

How to take care of my iPhone's Battery?

I hear a lot of things.
Such as keeping it at a high level will help boost its battery life.
While I also hear that if you drain it out occasionally, it will also boost.
Which of those is true?

IPhone 4 does not find any Wi-Fi?

I got the iPhone 4 today and it is not picking up any Wi-Fi signals. I know that it is not my internet router because the Wi-Fi on my parents' phones works and it also worked on my iPhone 3G earlier today before I got the 4. I have the Wi-Fi button on and the "ask to join networks" on as well, but even when I pull up an app or safari, it does not give me any suggestions. I have reset the network settings and I'm still having the same problem!
Has anyone else had this problem and how did you fix it?

How to retrieve lost itunes music?

I recently lost my iphone which i bought several songs on from itunes. Is there a way I can recover the purchases i made that were not synced to my computer?