you cant own NPCs. You'll be able to give them commands, if they agree to team up with you. How that works is still unknown. But NPCs are meant to be just like players, so they will only work for you, if they profit from it more than by doing their own jobs.

You hire an NPC via a contract whereby they do something for you (offer you a service) and then you pay them for it. When it comes to commanding them, well, let's just say you can ask them to do something but if they don't want to they wont and if they do they will. They have minds of their own afterall.

If you tell them to run into a fight that looks like a suicide run they probably wont wanna do it.

NPCs can be hired for a broad range of activities and on a broad range of terms under the contract system. They will probably perform those tasks autonomously, but you might be able to give them fairly detailed instructions, either through contract terms or through something like the scripts that operate as task setting rules for OPCs (player characters that persist in the world when the player is offline).

Contracts are described in DJ 7, which is still (I think) the last word in the subject. Offline Player Characters are described in DJ 3.

I have a long post analyzing contracts.

https://chroniclesofelyria.com/forum/topic/30605/of-contracts-and-commerce-a-tldnr-post

NPCs will be modeled psychologically (again based on last word). Markof’s post on that from a year and a half ago is still the best analysis.

https://chroniclesofelyria.com/forum/topic/22078/lets-try-to-understand-our-neighbors-the-npcs