Recourse for poor estate administration?

I'm one of 6 beneficiaries named in a MA estate; decedent's date of death was in 2008. The executor never filed an inventory with Probate, and beneficiaries have received only a partial accounting through 2009. Typical estate expenses were paid by the executor, but he's also claiming exorbitant "administration" charges (his time, travel, etc.) for which he expects to be compensated. We have no idea what's been added to his "bill" since. Real Estate from the estate is currently for sale. Should we wait for a final accounting, or should we put Probate on notice now, letting the court know things haven't been done properly? With regard to the missing estate inventory - will it by our word against his as to what the decendent actually owned?