Mick, I don't think Nationalists or Ulstermen in themselves have ever been the problem. It has just been very difficult for ordinary people of either "side" to envisage making peace, when there is a risk that the father will be shot in front of the children at Sunday dinner. (The UDA and the IRA both did this in the past). Peace does seem to be within reach - although it is still some way off - and yes, the weapons of the UDA and attendant splinter groups have to go as well. Has there been any monitoring of that? Maybe the Nationalist community could press harder on that issue. They should have a good chance of forcing it. If their guns have gone away, they can demand their rights as a simple issue of law and order.
At the end of the day, the problems of Northern Ireland will be solved by the communities who live there. The British can't solve them. If I were in a position of power, I would be tempted to light a fire under the Ulster Protestants' behinds, by telling them that they had (say) two years you make peace with their neighbours. Then, if they had not reached a workable agreement, they would have full independence - whether they wanted it or not. Believe me, very few Brits on the mainland have a deep sentimental yearning to keep Ulster within the UK!