How do you decide what to get S1 to buy in to?

I already explained: you select options by comparing their positive traits. The devil is in the details, of course, but as you might imagine I do entire training CDs on this stuff. I've also written a few blog articles about this in the past.

What do you do in situations where feedback comes too late (long term investments with distant payoffs) or never (e.g. ethical decisions where the world will never let you know whether you're right or not).

I don't understand the question. If you're asking how I'd know whether I made the best possible decision, I wouldn't. Maximizers do very badly at long-term happiness, so I've taught myself to be a satisficer. I assume that the decision to invest something for the long term is better than investing nothing, and that regarding an ethical decision I will know by the consequences and my regrets or lack thereof whether I've done the "right thing"... and I probably won't have to wait very long for that feedback.