1 - Did you try to disassociate the cache on the SSD? BE VERY, VERY CAREFUL!!! - I don't know if this will erase your drive or not!!! Do you have any tests that you can run from the manufacturer? Is the SSD still under warranty? If so, you may be able to contact the manufacturer and swap it for another one.
2 - The fixed USB-IF xHCI USB Host Controller is actually buried deep inside Device Manager - but it's OK, otherwise it'd show as an error and you would see it.
3 - If you're not attached to the Cyberlink software - uninstall it. If you are, then leave it be and we'll try to work around it. I haven't seen any specific issues associated with this software and Win8 (other than it being a lot older than Windows 8).
Differing BSOD errors can be indicative of a lot of different things. Since the blame remains consistently on iastora.sys I have to suspect the storage sub-system. Since you've updated the drivers, the most likely problem areas are the hard drives or the motherboard.
- please run this hard drive diagnostic on the Western Digital drive: Hard Drive Diagnostic Procedure (I suggest there that you use the Seagate SeaTools test rather than the Western Digital test).
- contact the SSD manufacturer to see what options you have through them.
- zip up and upload the contents of the C:\Windows\Minidump directory for us to have a look at.
