Begin by instructing your attorney to demand copy of trust, interpret your rights, take appropriate action.

Second marriage is void. Mexican citizen may bring action in California.

You may have creditors claim against estate. Much more case specific information needed to further opine.

Do not take legal advice from bank trust officer. Much more case specific information needed to assess and provide opinion.

No. You are entitled to notice and renter rights which include notice. Consult eviction defense counsel.

Probably not. General rule is that new spouse not liable for debts incurred by spouse prior to marriage. Many exceptions to general rule. Review...

Probably. If trust remains revocable and amendable, you may amend to change successor trustee and beneficiaries.

Your authority to o cash check depends on terms of POA. i need to review POA to further advise.

Inheritance income not taxable. Mother needs her own attorney to structure payment and agreement with executors as inheritance.

Probably. Biological parents entitled to notice in guardianship matter. Link explains: https://www.courts.ca.gov/selfhelp-guardianship.htm