Faction NPC's "Man" and "Woman" need vanilla Villager AI attaching to them.

closing, npcs go home when it's night and rain and monsters don't actually attack neutral NPCs.

Do you mean trade, jobs, breed, iron-golem spawn, avoid mobs ?
All of the above ?
Or running around looking derpy ?

Running around looking derpy, return to houses when night / rain - is enough. avoid monsters would be good too.

Don't need trade, jobs, breed or golem spawn.