One thing that seems fascinating about the rules of the monastic life, the rules of poverty and celibacy, and so forth, is that as strict as the rules are, it seems that compliance is voluntary. A monk could, at any moment, choose to disrobe and leave the order, and he would still be welcome to hear the Buddha and practice as a lay believer.
It seems almost as if he is lauded for acknowledging his limitations rather than continuing to struggle without making progress, and continuing to eat the alms food in vain. I haven't yet read any sutras where a lapsed monk is told that he earned himself a rebirth in a bad destination.
Am I mistaken? Does a lapsed monk earn bad karma from leaving the order, or from having mistakenly joined the monastic order? On the other hand, is it possible that he earns good karma and a good rebirth for having been in the Sangha? Suppose that his time in the Sangha makes him more wise, compassionate, forbearing as a lay person than he was previously.
Suppose a recently divorced banker or stock broker resolves to join an established Therevadin order for exactly seven years. He will memorize the teaching and meticulously follow the rules during that time, after which he will return to his profession (and find a new wife).
Is this permissible and beneficial, according to the Dhamma?