Is it obligatory to destroy religious files that were acquired through unlawful means, knowing that they are sold in markets, considered beneficial knowledge, and their creators expended effort in preparing them? And is it obligatory to postpone seeking knowledge about marriage if it causes seminal discharge and affects the performance of prayer?

The preponderant view among many scholars is that it is forbidden to copy software whose owners prohibit its copying except with their permission, based on the Prophet's saying: "Muslims are bound by their conditions," and "The property of a Muslim person is not lawful unless given with his willing consent." As for the religious programs you copied, it is not permissible for you to possess them unless you seek the owners' permission or know of their consent. Otherwise, you must compensate them financially.

Seeking knowledge is an obligation and should not be postponed. What is discharged from you when reading about marriage matters is considered to invalidate ablution (wudu') and nullify prayer, unless its discharge is continuous, in which case it falls under the ruling of incontinence (sals). You should perform ablution and pray, and what is discharged during prayer will not harm you.