You could put the drive into an external USB enclosure and connect it to another mac (or the same mac after replacing the drive) to see if you can read the data and copy it off. Then you can put another new drive in the enclosure and use it for time machine backups :)

I doubt they physically removed the memory, the chips are soldered onto the board and they would have to open up the iPad to get at them. They may have wiped the memory which could leave the iPad in an unusable state, but you can connect it to a computer running iTunes and reinstall iOS from there (use the "restore" button). Failing that you can try putting the iPad into DFU mode to force a firmware update. To do this plug the iPad into iTunes, then press and hold the power and home buttons. After 10 seconds release the power button, then after another 5 seconds release the home button. iTunes should pop up a message saying it has detected a device in recovery mode and allow you to reinstall iOS from there.

If you have a Mac you can use the Apple Configurator program from the Mac App Store to lock down any iPhone, iPad, or iPod Touch in all sorts of ways, including disabling wifi and preventing anyone from turning it back on (except you of course). For windows there is the iPhone Configuration Utility which may be able to do the same things. Apple iOS Enterprise Resources

Sound to me like a hardware problem, likely something is stuck on a disc sensor arm inside the drive. I say pull the computer apart and take the drive out. Then open up the drive and see if anything inside looks amiss (something stuck in there, arms not moving, etc.) Let us all know how you got on Relevant guides: iMac Intel 21.5" EMC 2308 Optical Drive Replacement Technique: Optical Drive Disc Removal Technique

These printers will say "out of paper" when they can't pick up paper. ie. there's no sensor to detect if there's actually paper in the tray, it just tries to pick up paper and errors if it didn't pick any up. Most likely the pickup rollers just aren't gripping the paper well enough. You may be able to clean them by reaching in though the front with a damp cloth (isopropyl alcohol works better). If there's a removable piece on the back of the printer then that will give better access to the rollers.

If it allows emergency call then it's not the antenna, more likely the sim card. Try taking out, cleaning, and reinserting the sim card, and try the sim card in another phone to check if it's ok. Failing that it could be the sim card holder in the phone.