Only option that I personally know of is to remove the back plate and remove battery connection. Then reconnect and turn on by plugging into a wall socket. If the phone is on you can use assistive touch in settings. Hope this helps, Josh

It is not, Here is the guide for the iPod touch 4th generation. Cheers

Not sure if I got lucky or if this is a fix. All I did was put phone in recovery mode and use my own downloaded ipsw. You can find any version you want here. Steps: Put iphone in recovery mode. Plug into computer, let iTunes discover recovery mode phone. Press and hold the shift and alt button as you click restore. Find and select downloaded ipsw. Restore. I hope this works, might not but did for me :)

Proximity sensor will not work if the "box" rubber piece is missing. I seen this in a YouTube video, here it is. Refer to 7:45 for the note. http://m.youtube.com/watch?v=G1D2WB5tekQ

By Internet function, I believe you are referring to the cellular data. Yes you can. Go to Settings, Then to General, Then Network, Turn off Cellular Data. Cheers, now you have a texting and calling only iPhone.

You're solder pads are most definatly off and there is no way to fix other than jumper wires. Sorry and goodluck!

You need to replace the power and proximity sensor flex cable. Here is the guide. iPhone 4 Power & Lock Button Replacement The part is under relevant parts. Hope this helps, Josh

Possibly your SIM card, or the connection for your SIM card reader to your motherboard. Not sure if this was removed but I know the iPhone 3GS you have to remove a lot to replace the battery. Hope this helps you. Josh

This is a common issue for iPods and iPhones. With wear and tear it gets stuck and does not pop back up. For iPhone it is easy to fix as you can just replace a small cable. For this iPod this is all I could find, doesn't look to promising but helpful if you're good with small parts. A temporarily fix is to insert a very small piece of paper in between the cable and lock button after taking iPod apart. This would force it back up and sometimes works again after playing with it. Not recommended but depends on priorities. Another temporary "fix" is on iOS 6+ you can get assistive touch which can be used to lock your screen and turn it off. Go to Settings, Go to General, Go to Accessibilty, Under heading: Physical & Motor Select Assistive touch Turn on. Hope this helped you. Josh

Time to either test your solder skills, get an expert to solder together or look on ebay and get them to solder back together. Only fix I have seen, also has happened to me. Good luck