well into the future
1. If communicated properly, they're capable of changing, forever, how someone thinks about the world, and shaping their actions both now and well into the future.
What does "well into the future" mean?

2. You have to give context, share examples, make it vivid. So pick one idea, and make it the through-line running through your entire talk, so that everything you say links back to it in some way.
What does "through-line" mean?

Question

well into the future
1. If communicated properly, they're capable of changing, forever, how someone thinks about the world, and shaping their actions both now and well into the future.
    What does "well into the future" mean?

2. You have to give context, share examples, make it vivid. So pick one idea, and make it the through-line running through your entire talk, so that everything you say links back to it in some way.
     What does "through-line" mean?

Answer

1. "well into the future" = "from now until a long time into the future"

2. "through-line" is not a standard noun phrase and seems awkward to me. In the sentence it means "theme"