IMac - slow to boot, bluetooth not found.

Question

System:
iMac 24" (Early 2009) 2.66GHz
8 GB 1067 MHz DDR3 memory (upgraded from original 4GB with 3rd party memory about 4 years ago)
Seagate Barracuda ST1000DM003 1TB Disk (upgraded from original 640GB about 2 years ago)
NVIDIA GeForge 9400
OS X: 10.10.1
The issue began about 3 months ago when my mother-in-law had the machine. According to her, the machine became very slow to boot (taking from 20min to over 1 hour) and her wireless mouse was not working. Fortunately she was already using a wired keyboard and had a spare wired mouse, so she was able to use the machine. Other than the slow boot and mouse issue, the system was stable.  We decided to replace her machine in any case, primarily because it's not easily serviceable - especially where she lives (rural Alabama). I took the machine back (it had been mine originally). At that point it was running 10.8.5.
I observed the following:
1) The system was, indeed, very slow to boot as she described.
2) None of the bluetooth devices were working.
3) The bluetooth device shows as "No information found" in the System Information report
4) Bluetooth preferences were not visible in system preferences.
5) Coincident with her first report or problems, the following messages began appearing in the system logs:
Dec 30 14:25:05 localhost kernel[0]: USBF:    3.195    AppleUSBHubPort::FatalError - Port 3 of Hub at 0x6100000 reported error 0xe00002c0 while doing clearing port feature (1)
Dec 30 14:25:05 localhost kernel[0]: USBF:    3.195    AppleUSBHubPort::FatalError - Port 1 of Hub at 0x6100000 reported error 0xe00002c0 while doing clearing port feature (1)
Dec 30 14:25:05 localhost kernel[0]: USBF:    3.206    AppleUSBHubPort::FatalError - Port 2 of Hub at 0x6100000 reported error 0xe00002ed while doing getting port status (4)
Dec 30 14:25:05 localhost kernel[0]: USBF:    3.206    AppleUSBHubPort::FatalError - Port 2 of Hub at 0x6100000 reported error 0xe00002c0 while doing clearing port feature (2)
Though she originally had external peripherals attached, all have been removed - the only things plugged into any USB or Firewire port are the keyboard and mouse.
So, that's how the machine was when I got it back... I have tried the following:
1) First I tried AHT - booting from the original disks provided with the system (AHT version 3A170). AHT hung while probing system hardware; it just stalled for several hours (I think I let it try overnight, only to return to see no progress). I've tried AHT a couple of times through this ordeal and can never get to the point where I can even initiate the test.
2) I tried removing the bluetooth preferences file.
3) I tried resetting NVRAM
4) I tried resetting SMC
5) I've booted in verbose mode, but nothing really stood out as clearly (or even vaguely) indicating a problem.
People did suggest booting in "safe" mode - thought it was never clear what I was supposed to do after that. In any case, an attempt to boot in safe mode caused the machine to just reboot itself. I even set safe mode in the boot-args and sat back and watched as the machine consistently rebooted itself each time... about 7 or 8 times before I got sick of hearing the boot chime. I did have verbose mode turned on in boot-args as well, an each time it rebooted at the same point, while initializing drivers. Interestingly, booting in "normal" mode has never been an issue - save for the exceptional amount of time it takes.
Since the data on the disk was of no use to me, I created a 10.10.1 install package on a USB stick and installed fresh - verifying and reformatting the hard drive before performing the install. The installation was uneventful (i.e. worked just like it should).
So, now I am running 10.10.1 and still no Bluetooth. I tried the AHT again and again it gets hung probing the hardware and I can't even initiate the test. I even tried a suggestion from another thread (hold ctl-shift-option and the power button for about 6 sec while the power is off)... that had worked for a number of folks but not for me.
One other piece of info I just confirmed while writing this, 0x6100000 is the Location ID associated with the BRCM2046 Hub - i.e. the Bluetooth device. Why this shows up as a hub on the USB Bus but the device itself doesn't appear to exist is confusing. I certainly would expect to see this as a USB hub on a correctly functioning system, it's just confusing why it's there when the underlying bluetooth device is not recognized.
So, I am pretty much convinced it's a hardware issue of some kind - given this is a "spare" Mac that I was simply trying to re-purpose to host a film scanner that requires a FireWire interface, I am not sure how much I want to invest financially in getting this resolved. I have heard that Apple no longer services these machines, but I could be wrong...  As I see it my options are kind of limited:
1) Take it to a repair facility (even if Apple doesn't work on them, there are at least 2 places near by that do) and pay them $$ just to tell me that it's going to be $$$ fix it.
2) Get my hands dirty, open this thing up and see if I can fix it.
I'm leaning towards option 2, but I am really reluctant to go on a fishing expedition. Based on what I have observed, it seems to be a problem with the bluetooth module itself, and as I understand it that is a separate part from the main logic board... which means that I can replace it for about $35 and the cost of the right tools; which all together total about the same amount as the "diagnostic" fee any local repair shop would charge. If it's not that, then it's the logic board and the best price I can find for that puts it in the "not worth the trouble" category anyway. I don't want to rule out some other component - memory, disk drive, or power supply... but any of those, at least to me, seem like the kind of components which would cause more erratic behavior when they fail.
So, what's my question - simple ... have I missed something here. Before I perform open heart surgery are there any last tricks I can try or is my conclusion that this must be a hardware problem pretty solid?

Answer 1

If your EHDs are formatted OS X Extended (journaled) and your using them as normal EHDs you don't need all of the WD software installed. The OS can use the disks without it.  Uninstall all of the WD software:
WDSecurityHelper    Application  (/Applications/WD Security.app/Contents/WDSecurityHelper.app)
WDDriveUtilityHelper    UNKNOWN  (missing value)
WDDriveUtilityHelper    Application  (/Applications/WD Drive