Will an iPhone break in my back pocket?

I carry so much crap in my pockets that I end up putting my phone in my back pocket.iPhones seem to be famous for the fact that the screen cracks insanely easily, so will it break when I sit on it?

Problem in restoring from backup with itunes?

I just restored my iphone 3g with itunes and after that i want to restore from a backup but itunes is asking for a password when i try to restore the backup but i didn't even encrypt a password

My itunes is running incredibly slow lately on my Mac?

Yeah. On my Mac. It's not even a Macbook Pro. It's a desktop. It was running perfectly fine up until 2 or 3 days ago and suddenly… Kaput. It's updating info extremely slowly, it's taking FOREVER to sync even 2 or 3 albums to my iphone… (as in the upper side of 45 minutes) and I have no idea why. The memory space is 1TB with a little over 225 gigs left available, I have 199.23 gigs of music in my itunes (almost 80 days worth), and that hasn't been a problem at all so I really don't know what's going on.

Unlocked iPhone 4 on T-mobile plan?

I'm planning on buying a unlocked iPhone 4 from ebay. However, I want to know if the unlocked iPhone 4 would;
- Call and text for free?
- Use internet (wi-fi only)?
- Download apps from the app store?
- It is a smartphone, will T-mobile charge me extra or charge a smartphone value plan on me if I use it for their network?

I'm currently with T-mobile and have the family plan in effect. I would get an android, but I like the iPhone much better and I don't want to pay extra $$$ for every month for the smartphone plan since I barely use 4G internet outside or inside. I already asked many people around me and tried searching it online, but they all have different answers.