Shakespeare (2) - More on "Measure for Measure," a Very Puzzling Play

Shakespeare's language is hard for us, not only because of the vocabulary, but also because of the syntax. Look at the Vicentio's first speech:

Of government the properties to unfold,
Would seem in me to affect speech and discourse;
Since I am put to know that your own science
Exceeds, in that, the lists of all advice
My strength can give you:

Vicentio is telling Escalus, his trusted minister, that he has nothing to tell him about government, which is an odd way to begin a comedy - and Measure for Measure is, in form, a comedy. Is Shakespeare telling us that, in this play, he intends to unfold the properties of government? Is that what this play is going to be about? Can a play about sex and hypocrisy also be about law and government? These questions will  perturb the audience (and the virtual audience, the readers) almost until the end.

As usual in Shakespeare, things get moving very fast in the first act. Vincentio summons Angelo and praises him for leading a virtuous life:

There is a kind of character in thy life,
That to the observer doth thy history
Fully unfold.

Those of us who have seen or read the play already know that Angelo, aside from his despicable behavior in the play itself, has also jilted a woman because her dowry was lost at sea, and we know that Vicentio knows it. So why does he have such a high opinion of Angelo? In Vicentio's opinion, is it acceptable to treat one's fiancee that way? According to the norms of Elizabethan England, is this proper? Or, is the entire business that Vincentio sets in motion and directs mainly intended to show Angelo up?

In any event, he appoints Angelo to replace him while he is absent from Vienna: "In our remove be thou at full ourself," He then admonishes him:

Mortality and mercy in Vienna
Live in thy tongue and heart.

Which is precisely the opposite of what will happen.