The issue that started the war was tax related. The tax the colonists paid to the crown went for protection of the colonies. The tax amount was small , insignificant compared to tax paid by the British citizens in Britain , yet the principle was the case. Moreover the colonist had no representatives in the British parliaments , which they demanded. This two issues were interrelate. Why pay taxes when you have no representation the parliament. The British refused the demands and that was the main point which led to the outbreak of the revolution
I dont think that the British had any chance to hold the colonies .Even if they granted them the places in the parliament , sooner or later another issue would pop up to give the Americans the reason to separate.