For 'bosom' Theobald read bottom. In Holingshed the King's words are, "Which words conceived within the secret bottom of my conscience," which I think settles the question. We have also, "Twill purge the bottoms of their consciences" (Fletch. Span. Cur. iv. 5).
"Yea with a splitting power, and made to tremble."
The folio has spitting; the correction was made in the 2nd folio.
Act III.
Sc. 1.
"Seek me out, and in that way I am wife in."
"I am sorry my integrity should breed