IPhone 4 with Straight Talk? - 1

Okay so right now I have a different straight talk phone; lets call it phone A. I would like to buy an iPhone 4 (lets call it phone B) from somebody. If I take my sim card from phone A, and put it in Phone B, then connect the iPhone to iTunes, will it work?
Do I have to "unlock it?"

This site may harm your computer?

Ok so, i went on my iphone today. I went on safari to just search some stuff up, and when i did most of the sites said " visiting this site may harm your computer". That never happened before and i also thought that apple products don't get viruses. Those messages are on a bunch of sites that had no problem before.

Can username be found with iPhone IP address?

Can I find out AOL screen names with iPhone IP?
I need to figure what my husband is doing on his private AOL acct but I can't figure out his username or screen name. Is there any way if finding out maybe with IP address of his iPhone? I don't mean to be stalkerish but I'm 5 months preg & we have a 2 year son whom I need to look out for & if he's cheating I need to take care of things now instead of later. Any help appreciated.

Can i sell my locked iPhone 5?

So my mom got an iPhone 5 on a line with four other people on Verizon about 3 weeks ago. The one who was in charge of the line was supposed to collect the money from the other people, including my mom, but she never paid the money to Verizon (took all the money for herself) and ended up owing $2000… I do not know why mother got a line with this woman and it was careless I know… The woman disappeared and is now impossible to get in touch with. Does anyone know what I could do with this phone now? I was thinking about unlocking it, but I found out that you can't do it with Verizon… Now I want to sell it on eBay but I have no idea how to sell it. Can I sell it locked? I can't take the number out or anything because the account is suspended… Can someone please help me figure out what to do or how to sell it?