A This is a matter for the employer to decide in the light of the circumstances. Obviously, there are some offence which would immediately disqualify someone from holding a teaching post, but others may be less clear-cut.
The first thing you should do is to interview the teacher to hear his explanation of his conduct. It may be that, as sometimes happens, he was involved in some unseemly student activity or perhaps in a protest group. The fact that it happened twice needs to be looked at.
In the end, you have to decide whether the conduct was such as to block perhaps for good, this young man's entry into his chosen profession.
Q What are the rules governing leave of absence for teachers to attend weddings, funerals, etc?
A There are no national agreements. The "Burgundy Book" on teachers' conditions of service makes provision for leave of absence for examinations, jury service and other public duties and for accredited union representatives, but leaves other matter to the discretion of the employer.
Some local education authorities and governing bodies have established their own policies for leave of absence, specifying when the entitlement is with, and when without, salary. Others leave decisions to the head's discretion. Such policies characteristically spell out the closeness of family relationships to which they apply and the maximum permitted period of absence. Generally, it is useful to have a policy to which one can refer when making decisions, otherwise there is always the risk of setting up precedents which may later prove embarrassing.
Whatever policies are established, it is always wise to allow a head some discretionary freedom to exercise compassion in specific cases which may fall outside the rules.