Non-custodial parent's death does not terminate his or her child support obliogation. There are many cases dated back to 1949 (Taylor v George). However, to collect child support against his estate, you must go back to the family court which ordered the child support and modify the child support. The court will determine a guideline child support and how the amount should be paid from the trust. The best way for you to deal with the modification is to contact department of child support services and let the government handle the modification and enforcement. The department can put a lien on the trust, foreclose the house, if necessary, to pay off child support arrearage and future supports.
Your spousal claim, however, is terminated upon his death.
Bear in mind that the current situation may well be due to the fact that the divorce action was terminated. The correct way is to let both probate court and the family court handle property division, even if he died before the final judgment. This way, if the house was funded by any of the community property, you would be entitled to some. There is a major difference between a family court and a probate court how the assets would be divided.
In terms of the trust, California probate code does not expressly prohibit a trustee being a beneficiary. In some cases this may be ok. However, there are so many traps. Duty of loyalty, commingling of property, duty to make trust property productive, impartiality to beneficiaries, etc, to name a few. I do not see how his parents would pass the legal muster of these trustee duties. You can gather evidence and consult a probate attorney whether there are enough grounds to remove the trustee. If so, you need to go back to the probate court petition the court.
