You can apply for your brother but will take 12-14 years for processing. Alternatively, asylum if in the US appears an option.

You should contact the Mexican consulate directly for guidance.

It can take 30-90 days for additional review of your documents.

The unlawful entry will require a waiver or return abroad for interview processing. Consult with an attorney for guidance.

This shouldn’t have any impact on your subsequent filings.

You may file for your daughter and her family.

Yes she may apply for a tourist visa.

Yes a change of status is possible while physically in the US.

You may apply for marriage based GC if marriage was entered into in good faith. Consult with an attorney for guidance.

Speak to a family law attorney for guidance.