I don't really see any bad advice either. Like I said everyone has their opinions. I like test tools. Whether the cause of the problems is the SATA cable or the HD is sort of irrelevant, because in both cases someone somewhere has to open the unit up to service it. I suppose that if somebody tried this once themselves and ended up breaking their own computer they might be apprehensive about opening something up or seeing others suggest it.
I was unaware of the CNET problem. I also mentioned MacUpdate. I'm also aware of Softpedia as sources of free stuff. Are there problems with these sites too?
If the drive isn't being seen by the system, remember to do the NVRAM reset if it hasn't been done already, (Command-Option-P-R held down at startup):
http://support.apple.com/kb/ht1379
I've run into drives that simply wouldn't be seen by the system until that was done. Another thing I can think of is that the USB drive isn't getting enough power. Around here it isn't uncommon for external drives to come with Windows drivers and custom backup software. It's supposed to be a feature but it's utterly useless to Macs. A final possibility might be that the drive is actually failing and is now to the point the system won't even acknowledge it.
If the system gets to the point where the drive is seen, I'd still recommend zeroing the drive as I described earlier before putting the OS on. If it's got so many bad sectors on it they can't be remapped any longer, depending on the drive, the controller may just leave entact and available for use, and Disk Utility may report the drive is unusable (may being the keyword there.)
Hope this helps,
Ciao