The Apple hardware test will test Apple hardware. Do not expect it to test anything non-Apple. SSDs in particular will usually show a failure code on most Macs, even though everything is good. You just move on, ignore failures that are related to third-party hardware. If your need to actually test that SSD, then you will need to use some other method.
Test storage (hard drive, SSD, etc) by formatting, then installing OS X, then boot your Mac from that drive. If that all works, then you likely have a good unit.
With all those different options that you tried, the best one would be to make sure you have a good drive, in a good external case. Install OS X on ANOTHER Mac to that external drive. Move that OS X boot drive to your MBPro5,5 and try to boot. It's not your SATA controller if it won't boot through USB or Firewire. If the drive won't work on ANY connection, external or internal - and you are sure it is good, then you have a problem with the MBPro logic board. It may not be worth fixing at this point, unless you can find a replacement logic board at a good price.