Chairs you can sit on? Add a plug-in to your server, you'll be a blue to sit on stairs.
No furniture? Not going to happen anyway. Mojang thinks of the game as a survival mode SURVIVAL game, not a building game. Detailed blocks will not be added to the game.
New types of NPCs? I don't know. Mobs don't do anything apart drop the occasional loot or try to kill you. NPCs are useless. I don't know if animals are NPCs but I do know that they are not fun, they're supposed to give you food.
I also have no idea what Menfolk villagers are and I don't want to look it up.