Does divorce occur in the three aforementioned cases, namely: swearing to divorce three times with the intention of emphasis, divorcing one's wife in a state of anger that led to unconsciousness, and the divorcer describing himself as "divorced" in writing to mislead another woman?

Swearing by divorce takes effect according to the majority of scholars if it is conditional. A triple divorce counts as three and makes the woman irrevocably divorced (baynunah kubra). Therefore, your wife is divorced by the entry of your brother's wife into your house. However, Ibn Taymiyyah is of the opinion that it does not constitute a divorce but rather requires you to pay an expiation for breaking an oath (kaffarat yamin).

As for your divorcing your wife, it takes effect as long as you are aware of what you are saying. Your informing someone that you are divorced does not constitute a divorce unless you intend to initiate one.

It is recommended to consult a Sharia court.