Yes you can. When a phone is deactivated, all that changes is you cannot use the phone to make phone calls or send texts from it unless you put an app that uses a Wi-Fi signal to do those two functions. All apps for all phone operating systems that work in a Wi-Fi environment will still work just fine.
Yes. The iPhone can operate like an iTouch without a SIM card or deactivated card installed. Just know whenever you turn the iPhone on it will either say "Waiting for Activation" or "No SIM Card Inserted". You can simply press your home key to bypass.
You also need to remember that by law, even a deactivated phone must be able to dial 911 and connect to emergency services. As long as the phone has power and there is a tower within its range. (Probably not a good idea to give to a young child to play with.)
I would almost say yes to all except for the wi fi. You would be able to use is as if it was in airplane mode.
yes, but not all iphone 4 apps are available on the iphone 3gs/3g/2g becuase they are too high resolution apps, or need a front facing camera.
Yes!!! :D Japanese iPhone apps work on English iPhones, but if they haven't set it up for English as well as Japanese, all the text will be in Japanese.
Yes, all of them. However, some Iphone apps will not work with the ipod touch, so be sure to check when in the app store.
yes u can transfer apps from ur iphone to the ipad!! Most applications will run in compatibility mode, but some have been rewritten to support natively both iPad and iPhone and are called Universal Binary.
Well, the iPhone 3g has a camera so any apps that have to do with that won't work. Other than that no.
iPhone Apps, including games, work only on iPhone, iPod Touch and some work on the iPad.
no, iphone apps are only made to work with iphones, not other phones...
Yes most of them are the same apps and will work on one or the other or both.
The app that you are trying to open may not be compatible with your version of iPod Touch software.For example, if you have the iPod Touch 3.0 software, a lot of apps will not work with it because the apps are not compatible with that specific software.Some apps state in their summary that it isn't compatible with certain iPod Touch software versions.
only games can
Yes. Yes they do. But apps with location services won't be able to find your location.
Many apps will work on the iPhone, iPad and iPod Touch. Some are written just for the iPad while others only work on the iPhone and iPod Touch. Under the title in the App Store it will specify which devices the app will work on.