As regards (i), I would recommend Janaki Sreedharan's well-argued document titled 'Imaging Vengeance: Amba and Draupadi in the Mahabharata', appearing in a fine anthology called 'Reflections and Variations on the Mahabharata', published by the Sahitya Academy (2004). The book is a handy digest for any serious Mb researcher. It should be available in the Sahitya Academy outlets in most of the Metros.
As regards (ii), honestly I cannot think of the Mb and its war without 'revenge' as one of its pervasive themes. The leitmotif of vengeance permeates almost all the intra-climactic deaths in the war: Shikhandi's role in the fall of Bheeshma; Dhrshtadyumna's vengeful beheading of an unarmed Drona in his yogic posture; Krshna's stringent admonition of a distracted Karna, reminding him of his abominable part in Draupadi's humiliation; Bheema redeeming his pledge of avenging Draupadi in the bloody killing of Duhshasana; Satyaki's decapitation of an armless Bhurishravas as the culmination of inter-familial vengeance; and Bheema's unfair felling of Duryodhana, again in redemption of his pledge to avenge Draupadi. [I have deliberately omitted Arjuna's killing of Jayadratha and Ashvatthama's gory nocturnal murders here, because the causes for these revenges originated during the war itself and not before it.]
Another point has been raised as to why Krshna/Yudhishthira made the peace negotiation in the Udyoga-Parva. Actually, one would see that the negotiation was formally initiated by Sanjaya (as Dhrtarashtra's representative), albeit after being nudged by Drupada's priest. That the Pandavas responded with their very reasonable counter-offer was apparently guided by a realisation of the looming danger of an utterly destructive fratricidal conflict. Duryodhana's rejection cleared Yudhishthira's conscience. The moot point is, had war been averted how would Bheema have redeemed his pledged revenge, enabling Draupadi to shed 'the signs of violation' she had preserved on her body (with its one piece of cloth marked with menstrual blood and dishevelled hair sacralised by the anointed Rajasuya waters), as a palpable notice for redemptive vengeance?