| Quote #1
This have I rumour'd through the peasant towns
When Rumour refers to the earl of Northumberland's castle as a "worm-eaten hold," the use of vivid imagery creates a sense of disease and decay that's associated with Northumberland's deception and betrayal. Northumberland has not only participated in efforts to overthrow the king (who was once his friend and ally), he also betrayed his own son when he phoned in sick instead of fighting at the battle at Shrewsbury in Part 1. So, when Rumour says the earl "lies crafty-sick," it implies that Northumberland has been faking his illness. (Lady Percy makes the same accusation later on in Act 2, Scene 3.) There's also a pun on "lies" at work here. It literally means that Northumberland has been laid up in bed and also emphasizes the point that he's a big old liar.
| Quote #2
When Northumberland learns two bits of terrible news (his son was killed in battle and the king's forces are on their way to Northumberland to arrest and/or kill him), he's suddenly feeling well enough to dispose of his "crutch" and get his battle on. (Funny how that happens. Too bad he wasn't inspired to fight sooner – his son might still be alive if he had.) Northumberland, who we have established is a big faker, indulges in a bit of crafty word play here as he insists that "in poison there is physic." In other words, the terrible news is like a "poison" to his system and makes him "sick" to hear it. The news has also left him feeling whoozy and weak in the knees. At the same time, he insists, this awful, sickening news has the effect of curing his (supposed) physical ailments (his "fever-weakened joints" and what not) because he's suddenly inspired to leap up and grab his weapon so he can fight the king.
| Quote #3
[…] But now the bishop
According to Morton, the Archbishop of York has quite the rebel following. Everyone thinks he's "sincere and holy" so he's managed to get his followers riled up against King Henry IV, who is responsible for the death of the late King Richard II. What's interesting to us about this passage is the way York tells his followers that the country "bleeds" and "gasps" for breath under the current king. The commonwealth of England was often imagined as a "body" politic and the Archbishop of York uses the idea that England is an ailing and suffering body as part of his propaganda.