I have spoken to a tech guy at Hobbyking, through their live chat system, and amazingly it was very useful. The guy was asking questions, watched the video, making suggestions, and very clearly knew his stuff. Got to hand it to HK, I'm pleasantly surprised.

He thought it might be ESC setup. I think by default the YEP150 is designed to run outrunners (the Align is in fact an outrunner enclosed in a case, I called it an inrunner to avoid confusion, this guy knew his stuff enough to point this out) which would make sense in that case. I don't have a programming card, but we're going to try and set up the PWM and timing to run the Turnigy as per his suggestions, via the Spektrum.

Will keep this posted, I hope we can solve it. Really don't want to have to get into ordering a replacement this late in the game!