Re: HELP my fileserver crashed!
I use lots of Western Digital drives, I've had to replace a couple over the years, most recently I just needed to fill out a web form, print the resulting RMA packing list and get a replacement a couple days later. No questions or quizzes, I don't recall ever having to use WD diagnostics to RMA a drive.
If it were me with your problem, I'd boot a live CD and see if the data is accessible without booting off the drive. Oh, and the more you run stuff like badblocks the more likely you'll have data loss. If there are bad sectors and the drive is failing, as it appears, get whatever is recoverable off as soon as possible, before trying to fix/diagnose the bad drive.
There are data recovery services that can recover your data off a completely inoperable drive, but they are pretty expensive.