I'm leaning towards a sticky wastegate as well. If it were fuel related, the behavior wouldn't be intermittent. The testing with the ALDA removed rules out anything with the overboost circuit or ALDA signal. When the indy couldn't move the wastegate rod with pliers, it may have already been stuck open (and therefore would not extend further). I'd mark the wastegate rod with a dab of paint, or magic marker, etc so you can tell what position it's in. If you have compressed air available, it would be nice to cycle the wastegate open & closed a few dozen times.
