I think your question about drives is a very good one. At the micro end of the artificial life spectrum (like in Tierra) I think it is answerable: a drive to survive and replicate, and a desire (for lack of a better term) for computer resources such as CPU cycles. Natural selection applies to alife just like to organic life.
As for AGI or superintelligent AI, who knows? The people who write about it hand-wave their way through all the difficult parts. Just because you can conceive of something doesn't mean it can exist. The idea that an AI could continually improve itself (how?) sounds like a perpetual motion machine to me.
> The idea that an AI could continually improve itself...
That's not that hard to imagine. AI-s are also limited by the laws of nature and they have limited capacity. Now if an AI wants to improve it needs more computational power which costs money in our world. So if an AI's goal is to improve itself, first it needs to make lots of money to keep its hardware running. If it can scale horizontally, then it's a simple order from Amazon to a rural farm.
As for AGI or superintelligent AI, who knows? The people who write about it hand-wave their way through all the difficult parts. Just because you can conceive of something doesn't mean it can exist. The idea that an AI could continually improve itself (how?) sounds like a perpetual motion machine to me.