RE your last question, yes, that, but also just to give you a literal stake in the platform. You could of course choose to cash out your earnings from this post pay out and take them off platform, but you could also convert the post earnings to Steem and "power up" to give you more steem power (stake) with which to use the platform. As the Steem network experiences more use, the lowest stake accounts are frozen out of using the network because of bandwidth shortages. This is already happening now in periods of peak use - users with less than 40 SP are often experiencing negative bandwidth as higher stake users are prioritized when use of the network exceeds bandwidth. Curie gives quality authors (should they choose to power up) the stake necessary to continue using the platform.
Cheers - Carl