Quote 1
O monstrous beast, how like a swine he lies!
Grim death, how foul and loathsome is thine image!
Sirs, I will practice on this drunken man. (Induction.1.35-37)
The Lord's decision to punish Sly, by transforming him from a "beast" to a "nobleman," anticipates the way Petruchio will force Kate to change from a "shrew" to an "obedient wife." Both of these forced metamorphoses raise Kate and Sly to more acceptable social roles, but Shakespeare calls into question whether these changes are permanent or even genuine.
Quote 2
LORD
I know the boy will well usurp the grace,
Voice, gait, and action of a gentlewoman.
I long to hear him call the drunkard husband,
And how my men will stay themselves from laughter
When they do homage to this simple peasant. (Induction.1.136-141)
Part of the Lord's elaborate plot to turn Sly from a "swine" into a nobleman involves the transformation of his servants (and himself) into role-playing characters, a reminder that all actors (including Shakespeare) undergo transformations each time they set foot on stage.
Quote 3
LORD
Persuade him that he hath been lunatic,
And when he says he is, say that he dreams,
For he is nothing but a mighty lord.
This do and do it kindly, gentle sirs.
It will be pastime passing excellent,
If it be husbanded with modesty. (Induction.1.66-71)
The Lord's motivation for playing an elaborate and cruel joke is somewhat fuzzy. Does he do it to teach Sly a lesson? What will Sly learn? Or, is it simply to humiliate him and have some fun at the expense of a powerless, lower-class figure? The fact that the joke will be a "pastime passing excellent" is a bit of an inside joke – Elizabethan theater was one of the most popular forms of "pastime."
Useful history snack: Bear baiting (tying up a bear and then releasing a pack of dogs on it while people watched from the bleachers) was another fun Elizabethan "pastime." In fact, Christopher Sly reveals that one of his many lame jobs was "bear keeper," the guy who fed and cleaned up after bears used in baiting contests.
Quote 4
LORD
Sirrah, go you to Bartholomew, my page,
And see him dressed in all suits like a lady.
That done, conduct him to the drunkard's chamber,
And call him 'Madam,' do him obeisance.
Tell him from me, as he will win my love (Induction.1.110-114)
The Lord's decision to "cast" his page (a young servant boy) in the role of Sly's trophy wife calls our attention to Elizabethan stage, where all characters (male and female) were played by men or boy actors. Bartholomew was likely played by an attractive young boy, one pretty enough to convince Sly that he is a woman. We're supposed to laugh at Sly for being fooled but Shakespeare also points to the slipperiness of gender on stage.
Quote 5
LORD, to Servingman
Sirrah, go you to Bartholomew my page,
And see him dressed in all suits like a lady.
That done, conduct him to the drunkard's chamber,
And call him 'Madam,' do him obeisance. (Induction.1.110-113)
Bart plays a very brief but important role in Shrew. The fact that it's so easy for him to pass as a woman suggests the fluidity of gender ("femininity" and "masculinity"), especially on stage.
Quote 6
LORD
Take him up gently, and to bed with him, (Induction.1.75)
The physical movement from the tavern to the Lord's house traces the disparity between Sly's status as a poor beggar and the Lord's status as a landowner and nobleman. (It also says a lot about the flexibility of the physical stage.)
Quote 7
LORD, as Attendant
Thou art a lord, and nothing but a lord; (Induction.2.61)
The means by which the Lord and his crew convince Sly that he is a nobleman and not a beggar suggests that our identities, in part, are formed by the way other people treat us / behave toward us, and also by the names we are called. Sly is called a "Lord" and so he believes it. But that hardly makes Christopher Sly a nobleman, which suggests that some social identities are not as fluid or easily transgressed than others.