Roadmap is evolving, next major update will be Mistlands (completely new biome to compliment the existing 5 finished biomes.) On a path the reach 9 total completed biomes. Smaller updates to be released between biomes updates (instance based dungeons in the mountain biomes expected early 2022. )

Expect at least 2 years of further development, be happily surprised if it's less (or only slightly more) - just MHO

oh yeah , there are already "companions" in the game that you can control. They will guard you, they will fight for you, they will follow you, and they will die for you.

Will you be able to install an NPC shop keeper or wood cutter? Probably not, but just an educated guess.