What to look for to keep these seedlings alive?

[Roberta]

Watch that direct sun... a blast of sun can toast leaves in minutes, even on a mature plant (Been there, done that) These babies need indirect light only for now. There will be plenty of time to increase light gently, when they're bigger. Unless the leaves get noticeably dark green, they're getting what they need for now. One of the good things you have going for you is that with the approach of fall, sun angle will be lower and intensity reduced when you do start to introduce more light. But they grow slooowwwwly, so patience. The only plant-related hobby that takes longer to learn, and has a longer "feedback loop" to tell you that you have gotten it right is bonsai...