There is an answer to all of these issues in the Vinaya. Vinaya is the Monastic Discipline (code of ethics to be obeyed). In other words Vinaya is the disciplinary code of monks and nuns. For you and I, lay disciples, it is the 5 -8 precepts. Sadly in the present day Vinaya is not given a due prominence. That’s why many are not in a position to realize the true benefits of the Dhamma. The basic code of the monastic discipline, also called ‘Patimokkha’ contains 227 rules for monks and 311 for nuns. Some rules and practices were regarded by the Buddha as essential and foundational to the pursuit of his teachings. Others were devised on an ad hoc basis as the Buddha encountered various behavioral problems or disputes among his followers.
Depending on the severity of the error a novice (sāmaṇera) can be re-ordained of expelled.
A novice (sāmaṇera) re-accepted (reordained) if the mistake is corrected and not that severe. Then "Immediately the uposatha is to be done, the Pāṭimokkha is to be recited." — Mv.X.5.14. punishment should be rescinded. Physical punishment is not allowed. A bhikkhu may not hit or lift his hand against a novice any more than he can do so to any other unordained person (see Pc 74 & 75). Even playful rough-housing is forbidden. A bhikkhu incurs a dukkaṭa under Pc 52 for tickling a novice, and a dukkaṭa under Cv.V.31.2 for flicking a novice with his tooth wood.
Expulsion. As stated under Pc 70, a misbehaving novice may be subject to two types of expulsion: expulsion from his status as a novice and expulsion as a punishment. As with punishment, expulsion is the responsibility of the novice's mentor. Pc 70 covers the second form of expulsion.
"I allow a novice endowed with ten qualities to be expelled: He is a taker of life, he is a taker of what is not given, he engages in unchastity, he is a speaker of lies, he is a drinker of intoxicants, he speaks dispraise of the Buddha, he speaks dispraise of the Dhamma, he speaks dispraise of the Saṅgha, he holds wrong views, he is a molester of a bhikkhunī. I allow that a novice endowed with these ten qualities be expelled." — Mv.I.60
Rules for GOING-FORTH are….
"A boy less than 15 years old should not be given the Going-forth. Whoever should give it: an offense of wrong doing." — Mv.I.50.1 "I allow that a boy less than 15 years old be given the Going-forth if he is capable of chasing crows." — Mv.I.51.1
"A son without permission from his parents should not be given the Going-forth. Whoever should give it: an offense of wrong doing." — Mv.I.54.6
How a novice is to be ordained — Mv.I.54.3
"Bhikkhus, I allow the Going-forth for a novice by means of these three goings for refuge." — Mv.I.54.3