Halal/Haram Matters

You can eat from it as the sin is on the earner.

Kindly refer to the following link(s): https://www.assimalhakeem.net/are-we-allowed-to-wish-some-one-happy-birthday-although-we-dont-celebrate-it/

Such spots of blood do not affect the permissibility of eating such eggs.

This is not permissible.

One can continue whatever  he is doing while adhan is called.

Simply tell them they must not do this as it is forbidden! If they don’t listen, complain to the headmaster or the administration! The sin will be on them, not you.

Such a reason is not a valid reason.

If a person applies hoping to get the prize, this is gambling and prohibited. But if a person was already subscribed and wins it, this is permissible.

It is not allowed to attend such gatherings at all; whether for males or females.

Nothing else can be done, except to repent to Allah and to show deep remorse and to keep it covered all the time.