"Can I put a 3ds battery in a new 3ds and vice versa"に関する回答If there are the same model DS and battery you should be fine.
"Damage external & internal but not sure if the phone is done for"に関する回答Jay, I'm really sorry about your iPhone but with a bend in the iPhone you would have to do a lot more than replace the screen. You will have to replace the back of the iPhone and the MotherBoard and a bunch of other little thing because they are probably bent to. I'm supprised your Phone still works because were the bend is is almost were the sin tray is, the MotherBoard and other things. I know no everybody has cash to play with but I would get a new iPhone. Sorry if you didn't find what you were looking for.
"Phone Won't Activate Or Let Me Activate"に関する回答To put the iPhone into recovery mode you must plug the iPhone into a computer with iTunes, after having iTunes open and the iPhone plug in, hold the power button (sleep) and home button until iTunes opens the recovery mode for the iPhone. If you need to restart hold the power button (sleep) and home until the iPhone reboots. Also the SIM Card my be damaged (all it take to destroy a SIM Card is a scratch on the chip) You can also setup the iPhone through iTunes hope that helps :)