The most clear example of this is the concept of sufficient consensus in South Africa. This is the view that you can not possibly reach an agreement with all of the parties involved, but you can continue the process with a sufficient consensus of those involved. What may turn out to be the process in Northern Ireland that will have the most significance for some of the other processes are the Mitchell Principles. The idea of having a set of principles which people must sign before they enter the negotiations, principles having to do with handling the question and threat of violence resuming, is being considered by the Basques. Generally, these negotiators came to power because of their skill at handling security issues and not their skill at compromise.
Violence remains a serious obstacle to peace processes.
Ceasefires don't end violence. Typically, violence continues for two reasons. Spoiler violence by those who oppose settlement increase when compromise is in the air. Violence over a long period of time becomes a part of the culture. My money is on an agreement within the next month or two.