I don't know how you could limit a list like that to seven. There are DOZENS of completely inexplicable decisions Williams made that contributed to this team losing games.
Last week, for example, when the team is long out of contention. Tanner Roark has already given up a homerun to AJ Pierzynski. In the sixth inning, he wants the lineup to get to Roark's spot to ph for him. It doesn't so he sends Roark back out...to face Pierzynski again and gives up another homerun which turned out to be the winning margin. That's not the worst part. Roark doesn't even finish the inning! He goes to a reliever anyway and he gets pinch hit for in the next inning.
It's September. He has how many relievers in the bullpen? He could have used 1,2,3,4,5 relievers in the inning...a lefty for Pierzynski, at least, and it wouldn't have been much of a strain and then ph for the pitcher spot in the lineup. His decision making, too often, seems to have only made sense to him.
That's my first requirement for a manager. The new manager needs to be able to make quick, in-game decisions in a constantly changing environment and be able to explain them.