Quote 16
SHYLOCK
Why, look you, how you storm!
I would be friends with you, and have your love,
Forget the shames that you have stain'd me with,
Supply your present wants, and take no doit
Of usance for my moneys, and you'll not hear me.
This is kind I offer. (1.3.18)
Shylock's offer seems too generous not to come with a catch. Still, perhaps he's trying to be the bigger man of the two. He might be offering up his friendship, and seeking Antonio's, because he sees these unusual circumstances as a chance for the two to break their cultural isolation from each other.
Quote 17
SHYLOCK
I say my daughter is my flesh and my blood.
SALERIO
There is more difference between thy flesh and hers than
between jet and ivory; more between your bloods than there is
between red wine and Rhenish. But tell us, do you hear whether
Antonio have had any loss at sea or no? (3.1.4)
Even after Jessica's betrayal, Shylock still insists the girl is his flesh and blood. Salerio, in one savage swoop, challenges this notion by saying she's actually nothing like him at all. The proof of this is, implicitly, that Jessica chose to desert him. If Shylock held onto her as something close to him (which he obviously did, calling her his flesh and blood), then Salerio has brought home the realization that Shylock really is all alone in the world—even his flesh and blood has deserted him. Without recourse to get her back, it makes sense that he might seek the flesh and blood of another.
Quote 18
SHYLOCK
I pray you, give me leave to go from hence;
I am not well; send the deed after me
And I will sign it. (4.1.23)
Shylock has been stripped of absolutely everything, and he leaves the court to return to a life of lonely isolation. Depending on one's view of justice, and Shylock's original intentions, this is a fitting end. But if the play is about mercy, then Shylock's resolution is a note missing from the final chord. To simply cast Shylock out of the play is a dissatisfying ending for this central character.