If you’re still suffering this problem it seems to be a known issue documented on WD’s site: WD USB 3.0 hard drives disconnect or disappear when connected to a USB 3.0 hub Unless this is a common problem with all USB 3 drives I would of said the problem is with the WD drive for which an update should be issued for that, but hey you can try their suggestion.
On some machines there is a setting in the system bios to allow power to remain on to the USB ports while the machine is in a powered down state. If such a setting exists on your laptop then it could be all you need to change. Update (05/12/2016): A quick search online has lead me to Toshiba's sleep and charge feature which might be what you need: http://forums.toshiba.com/t5/General-Features-Knowledge-Base/About-the-Toshiba-Sleep-Utility-amp-USB-Sleep-and-Charge/ta-p/277937
Suppose the first step would be to completely wipe the device by restoring it to factory and not using a backup. Then ensure the sim is removed, charge it to 100% with the Apple charger then leave the device in standby overnight in flight mode and see how the battery behaves. If it still drains excessively there maybe a hardware issue. If it's better then reintroduce things back one by one to see when the performance changes, avoid doing a system restore.
Sounds like your drive is struggling to read the discs. Try installing the games to the hard drive and see if that's better. If it's the same it could be getting hot, therefore does it get worse the longer the machine is on, and has it ever frozen completely?
Maybe it's something basic like the cable you're using, or even the PC you are plugging it into. See if it registers on a friends PC with their cable. Assume the phone is otherwise functional. If not, and maybe if it is, putting it into DFU mode, does it behave differently?
It could be simply that something has got inside the slot and is preventing the card from seating properly. Shine a torch in the slot and see if you can see anything obstructing it. If not then its likely either dirt on the contacts or the cable inside has come loose, in which case it would have to be pulled apart. One clue might be how it failed, did it stop suddenly following a knock or drop or did it slowly become less and less reliable.
Ahh, you forgot to release the battery from the mounting before tearing the battery out. I did exactly the same thing with an iPhone 4 just before the 4s was released. In my case it actually tore the contacts from the board making it impossible to solder it back on. I tried, and had mixed results with the phone working for a few minutes at a time at best but my story does not have a happy ending. I ended up buying a new phone and giving away the 4 for spares in the end. Depending on the damage done, there might be a chance you can solder a new connector on if you have a good soldering iron. Replacement battery connectors can be obtained on eBay, I recall that's what I did. I'm just hoping you didn't loose the contacts from the board like I did.