How do you block apps from your iphone?
Around 150Â£ if you don't have warranty. If you do should be nothing
Can you buy apps from apps store on your iPhone 3g when unlocked and on tmobile?
I would believe so, it can be difficult to unlock your iphone though but the iphone is exclusively at tmobile in Europe.
Can you get apps from the apps store after jailbreaking your iPhone 3G?
you can still get it sometimes but sometimes the app store dose not work for example on my ipod it works but on my iphone it does not work
How do you transfer apps from itunes to iphone 4 without losing other apps on allready on iphone?
eBay would be your best bet
Can you transfer your music and apps from one unlocked and jail broken iPhone to your new one If so how do you?
No, iPhone uses iOS as its operating system.