1) Rowan Williams isn't all that "orthodox". He likes the pageantry and traditions and academic study of the fathers but he was always a bit on the liberal side in regards to the practice of the faith. He's toned his liberalism down since becoming Archbishop, because he does believe at the very least in the Catholicism of his church, but at the end of the day his sympathies lie more with tEC and Canadian Anglican Church.
2) While he could indeed lay more of a smackdown (say by disinviting the Episcopalian bishops from Lambeth and all Anglican functions), he cannot just excommunicate these churches on his own authority, not even for just the CofE. That said, were he to go ahead with that sort of proceeding he would have the majority of the Anglican Communion on his side, but he would never be able to get it that far, as he would be unable to get his own bishops in England to go along with it. As mentioned above, though, he believes in "Catholicism" in a rather twisted sense, and believes it's his job to get the liberals and conservatives (and low and high churches) to all sit around a table having tea and crumpets with a nice side of Anglican fudge, talking about rainbows and gumdrops and unicorns.
I for one would love to see the Queen take these matters into her own hand, all the reports I'd heard back in my own Anglican days were that she is most definitely not amused.