Would Vader or Pestage known of the Maw Cluster, or was that something Palp's and Tarkin kept to themselves.See now I totally buy that Pestage would know about it, for the simple fact that somebody would have to. Palpatine loved his intricate schemes too much for me to believe he'd leave the post-assassination trajectory of the Empire up to chance, and that means he'd need somebody acting as his proxy to make sure that nobody (coughVadercough) could stabilize things before the Reborn Emperor swooped in to do his dark messiah routine. Pestage had been acting as a loyal agent of the Sith since Plagueis was Master, and as far as I know never once waivered in his loyalty to Palpatine after he was originally swayed from Hego Damask's service.
Besides, Palpatine allowed him to handle much of the day to day running of the empire didn't he? Insofar as Palpatine could trust, I think he trusted Sate Pestage.
Heck, did Palp even know about the Maw Cluster? If he knew of it, it seems kinda odd he never tried to contact Daala during the Dark Empire campaigns.