If I update iTunes, will I lose the backup stored on it?

I recently purchased an iPhone 6. I previously had an iPhone 4S and an older version of iTunes. Before going to the Apple Store, I backed up my phone onto my laptop (not the cloud.) When I plugged in my 6 to restore the backup, a popup came up saying I had to update iTunes in order to sync this iPhone. I'm just wondering if the backup will be deleted if I update iTunes. Any help?

Do all Iphone apps need cellular data to run?

During one of my games, my Wi-Fi went down and it said I needed cellular data. Do I need this for every app or does it just say this for every app? I don't want any charges for not using the cellular data…

IN RE APPLE & AT&TM ANTITRUST LITIGATION?

Suppose your company's engineers figured out how to manufacture applications that worked on the iPhone or another Apple product. Should you manufacture and sell them, so you can share in some of Apple's success? Would such a move find support in antitrust law? On the other hand, is it possible without running afoul of antitrust laws for a competitor make a similar product?

Is this Christmas list reasonable? - 1

-iPod Touch (I got an iPod touch four years ago but I recently lost it in September. I have an iPhone 4S, but it only has 8 GB on the entire phone to hold apps, pictures, etc.)

-Onitsuka Mexico 66 Slip On sneakers in black

-Supernatural calendar for 2015

-Copics markers and or Prismacolor pencils

-All Time Low pullover shirt

-Sunrise Skater Kids shirt (It's by a Youtuber, so the shirt's only like ten dollars)

-an All Time Low and Fall Out Boy poster

I was going to ask my aunt for a Warped Tour ticket since they come out around Christmas time and are twenty dollars. Then I'd just ask my uncle for a gift card to Hot Topic.