Walthrough is the list of what to do to unlock the content but since the game is still in development, I haven't had time to add for all the NPCs yet. In the changelog, it is indicated when there is additional content and for which NPC. when the game is at V1.00, there will be content for all NPCs.
For the round trips, the resources of the 1st quest (when there is one) are basic resources so you must have some in your inventory and for the trip, it doesn't take much time.
I retested, before releasing on my paid page, the V0.18 and it takes me an average of 5 minutes per NPC to recruit them all. I'm counting on time to seek out the resources of the chambers.