blurring our "clear boundries"

Early on in our discussion of this play the idea was brought up that Measure for Measure was a work defined by extremes. there appears to be a 'precise' division between these characters in terms of who they are and where they stand. Having read on, I feel it is safe to say that this place isn't as definite as it many initially seem. Between the black and white is something in the middle. This is the reality of the situation, the conflict, the guts; there's that grayness, where the experience comes from. Some examples
Angelo, a character defined by his strict judgments and hard rulings, finds himself bending, quickly falling head-over-heels for Claudio's sister. He addresses this weakness directly; fully aware that this recent dreamy light footedness could very well damage the image that he has worked so hard to create for himself (2.4 20-29). This situation might have been seen as romantic (a very stubborn ruler being so taken with the beauty of a young woman that he is willing to step on himself a bit and show some mercy) if Angelo didn't end up being Angelo at the end of it all. If he would have turned on a dime, realizing that he could not deny the one for whom he feels so warmly for, knowing how badly hurt that person would otherwise be, than we would still be dealing with the idea of extremes. By forcing young Isabella, who is less than half as step away from the nunnery, to decide between her own virginity and her brother's life, we get the idea that we as still dealing with the thick-headed wannabe-somebody, only with a bit more (or less) than we might have originally thought. Moved by feelings that are beyond his control, Angelo feels the need to control the situation as best he can to get what he wants.
Claudio finds himself in jail awaiting death for impregnating Juliet. My first impression of him was one of an upstanding guy; going to jail over the couple's happening, not denying his actions or naming someone else as the child's true papa. With execution day rapidly approaching, he seems to maintain that same kind of dignity, slowly accepting his fate with a bit of hope floating around him. When Isabella shows up, visually shaken, she confirms that there is no way he can distance himself from the inevitable. This lets the reader know what she is expecting of her brother. She does mention Angelo's deal, in a "what a creep, eh?" kind of way. Claudio agrees and then insists that she go through with the creepy deal (and getting a verbal whipping from the nun-in-training). After the Duke (friar) tells him that Angelo would never have gone through with such a deal, we see the reemergence of our first Claudio (if a bit dented now) who wants nothing more then to apologize to his dear sister now that he knows for sure he's screwed.
So what is being said here? Shakespeare is giving us the complications that make life explode. He is bringing us as readers down to earth after setting us up for a flat representation of our own reality.