AndreaB, when you say you restricted all distributions until age 55, you mean no distributions at all til then, correct? A close friend has suggested this idea, too--only she said no distributions til 65. And if AS is still alive then and wants to blow it all on opiates, so be it.
OutToLunch, you make good points. Thank you for challenging my thinking. The goal as I see it is to give my AS--if the time ever comes when he chooses recovery--exactly what I would want to give him if I were alive: the best possible chance to make it, for example, treatment at a longterm recovery facility and the chance afterwards to go back to school without incurring debt. I am in no way considering allowing the trustee to pay his rent, etc. No recovery, no money. If no treatment and recovery, the contingent beneficiary would get every dime on AS's death.
What's tripping me up is the question of what long-term recovery looks like (if he ever gets that far). I'm in a quandary about trustee discretion, because a financial services company as trustee will not know my AS. Hence the idea of restricting trustee discretion, although I know AS could game any criteria. Plus, it does feel like "dead hand control." But the only other possible trustee would be my healthy son, and he wouldn't pull his brother out of a fire.
You guys are great--thank you so much! This is exactly the sort of discussion I was hoping for.