Answers to your three questions straight from enotes:
point of view- (The father)... keeps a journal through the ten years of their confinement on the island, and at the end of the tale...
climax - ...he gives the manuscript to his sons Fritz and Francis/Franz who are leaving for Europe. His remarks as he hands over his journal reflect the purpose of the book, as well as late eighteenth-century ideas about religion and morality:
'It will make me happy to think that my simple narrative may lead some [children] to observe how blessed are the results of patient continuance in well-doing, what benefits arise from the thoughtful application of knowledge and science, and how good and pleasant a thing it is when brethren dwell together in unity, under the eye of the parental love.'
Several commentators have noted the influence of the philosopher Jean Jacques Rousseau (1712-1778) on the didactic, or moralizing, purpose of the narrative....Rousseau regarded civilization as the root of all evil and believed that humans in their natural state were good...
Robinson Crusoe had to learn just as Rousseau thought children should learn: nature, kind to Crusoe, was the teacher. All these ideas are reflected in Wyss's didactic tale.