How we cite our quotes:
I would to God –
So my untruth had not provoked him to it –
The King had cut off my head with my brother's. (2.2.4)
Reflecting on the mess the kingdom is in, York takes a moment to wish his troubles were over. It's interesting that he actually recognizes that Richard beheaded his brother (something the king never quite admits), yet remains loyal to the guy. Why is that? That York remains a loyal subject for as long as he does with this mentality shows how weird the concept of loyalty has become under Richard's rule.
Why, foolish boy, the king is left behind,
And in my loyal bosom lies his power. (2.3.4)
York is telling Henry Bolingbroke here that he's out of line for coming back after he's been banished, and he's declaring himself the king's loyal representative. He's also making the title of king a transferable property. By suggesting that the king is "left behind" (meaning that he's left York as regent) and that Richard's power lies in his "bosom" (that is, on his person), he's implying that the king can be separated from his power.
It would beseem the Lord Northumberland
To say 'King Richard'. (3.3.1)
Even though he's gone over to Henry Bolingbroke's side, York scolds Northumberland for referring to Richard by his first name. York shows, even this late in the game, that he's deeply pained by the transfer of the title of king from one man to another.