Anyone can offer to change or "correct" any record. However, the drafter doesn't have to agree to the proposed changes or so-called "corrections."
Of course. But it is just normal everyday process criminal, and civil to let the other party have their say and rebuttal before a final report/verdict is reached. Not much new or exciting here. Usually the person making the findings welcomes it because it gives them a view into what the defenses will be if it goes to court.
Unless they are just trying to do a hit job and do some damage because they dont have a court case anyway, which might apply in charges against Trump.