First thoughts, all problematical

With what cruel purpose scripts this Duke his play?
It's quick he knows the truth, and yet he sits;
Adds his own falsehoods, one upon the next,
And only takes offense when he's blasphemed.

It's bad enough to lie yourself so oft;
It's worse, to urge a friend to the same crime;
The premise of the play's a lie concocted,
And all ends well - perhaps - but 'fore that time
Half this play's lies. Can he for them account?
His reckless words and cold, callous behavior
Would seem to profit little, harming much.

What profits it to let offenses lie -
ignore a wife much wronged, and let her weep;
drive maid to mourn a living brother's death -
when but the show of his own power's needed
to end all, fix the matter, and have done?

This monk's no monk - he only wears the habit,
and vows are more than cowls - yet he'll feign
Confessor to the damned, a falser witness
Than Lucio to he: this duke to men.

I'd call him coward, like the lingering juror,
Who dares not speak 'til assent's guaranteed;
T'would be a virtue in him to be dreadful,
But no, it seems this Duke's a useless weed
Best suited to be servant, not a leader,
Or else Angelo's right: and this man's mad.

...

You've likely guessed that I can't stand the Duke.