It is good to see intelligent people writing on intelligence...
Let me try to answer your questions as they are interesting for me also :
1- For definition of intelligence, I stick to Einstein's definition:
The true sign of intelligence is not knowledge but imagination.
Imagination is creating something unique without having the necessary inputs before.
2- Apart from humans no creature can do this yet. AI is on the way.
As the only way to fly is not to flap wings, the only intelligence is not human intelligence as we know it. This subject is huge for a comment.
3- Please post on life...i am following you and waitng for your writing.
The only issue I have is how can we confirm if something has imagination or not?
Thanks for your kind words!