How to transfer SIM card to iPhone 4?

My dad just gave me his old iPhone 4, since he just got the new 5, and I'm wondering how I can reassign the phone to my current one's (LG Rumour 2) number. I know that the iPhone 4 has a slot for the SIM card, but somehow I doubt it's as simple as popping the iPhone one out and putting in my LG Rumour one. Basically, I'm asking how I can set this up as a new iPhone with my old number (contacts don't matter that much since I don't have a lot). Does anyone know how I can do this? Any help is much appreciated.

How to stop iTunes from downloading?

A while back, when it was free, I "purchased" 10 episodes of the show "10 Things I Hate About You" from the iTunes store. I no longer want these episodes, but every time I plug in my iPhone, the episodes start downloading. I still want it to download my music and other purchases, I just never want to have to deal with those "10 Things… " episodes ever again. How can I stop this?

IPhone 5/iOS 6 (newest one) can you see who views your twitter?

I have an Instagram and no twitter but I looked at a guys Instagram and his twitter and so can he see if I looked at it? Like thru Instagram? Even tho I don't have a twitter can you still find out? And also can you since it's the new iOS 6 on an iPhone 5? Like can he see I viewed his twitter from my Instagram account?

Unlocked iphone for T-mobile

So before someone comments asking why I want an iPhone, & that i shoud get the Galaxy s3,
I already have it, & i'm not the biggest fan.
ALSO, before you say it isn't possbile, On the website it says Unlocked at&t iphones are compatiable.
At&t has been trying to purchase t-mobile for a while now, i believe & i think they finally have since they are now advertising at&t phones on the t-mobile webite.
So is it possible for me to go to the Apple store, purchase a white 8g iphone 4? Because its about $450 just for the 4. And is it possible to bring it into the t-mobile store to get it hooked up to t-mobile?
Please LET ME KNOW! Someone who works at t-mobile and actually knows or something!

Iphone messages isn't working?

So I went to send my friend a really long text by copying and pasting, but then messages froze up once I hit paste. Every time I open the messages app I get a white screen for about a minute then it crashes. I have tried restoring it and updating it but nothing seems to be working. Will I have to go to apple store to get it fixed?