arbozaliyan

Rocks, Durability Modifications, Long Term Food Storage and Welding, Masonry, and Electrical Skills  are my favorites.

when you say traps the first thing comes to my mind is holes. make holes, cover them, put a alarm clock or something that makes lots of noise, when zombies gather on the hole break the surface by using ropes or something else (like when you pull the rope it would unbalance the surface and they would fall in it). after that burn them or blow them or make just falling them kill them.

that is a good idea too.

Now that all zombies / corpses have standard clothing items in their inventories, I find it much more tedious to sift through their pockets. They carry valuable items sometimes, but clicking through a stack of bodies and noticing the odd extra item is difficult.
 
As we rarely need to loot more than 1 or 2 zombies / closets for clothing in an entire game session, I think it would be useful to have a clothing filter for these (and possibly other) containers that can be turned on and off, making it easier to spot items of interest.
 
I don't think this would be unrealistic or against the spirit of the game. If I were looting in real life, I would be able to ignore clothing when searching a body or a wardrobe for useful items.

So I was thinking about how you start out a game of Zomboid. Zomboid is meant to be hyper-realistic, but you begin the game with no family or friends who you want to look after. It's like you're literally plopped onto the world having never spoken to any other human before.
 
So here's my suggestion for when the NPCs are back in: During character creation, you can also choose whether or not your character has any "Family." Family members will include things like wife, husband, father, mother, brother, sister, best friend, grandparents, etc. If you choose to have them (let's say you pick to have 3 family members), all 3 will be placed on the map at random (though maybe all within the same town you start in). They get unique dialogue if you happen to find them, and while talking to other NPCs you can also ask about them to try and find out where they are.
 
This not only makes things more realistic and adds to roleplaying, it also adds a sort of optional sidequest - trying to track down and re-unite your family in the zombie apocalypse! Of course, if you're the lone survivor type, you can choose not to have any family at all.
 
Having family will have disadvantages - if you don't manage to track them down, you'll get the "Absent Family" negative moodlet as you miss them and wonder where they are. Your family are like any other NPC, and can die while you're not there - so if you track them down only to find a corpse, you get Depressed, but at least you know what's happened to them and your Depression should eventually wear off. The Absent Family moodlet, however, is persistent, and affects you when you're not busy with other tasks (perhaps could make it a more believable alternative to Bored?).
 
But if you do manage to find a family member, they'll start with a big boost to positive relations with you, making them a good option to join up with and unlikely to betray you! Also you'll get a positive moodlet from spending time with them.
 
...Although, of course, if they die, your character will get Depressed. That's another risk you have to weigh against the reward.

or you could just find a map of the local area while browsing around

For boobytraps or passive defense I was thinking of logs / planks studded with nails or axes swung down when triggered, though these would probably be complicated to build and endanger me as much as the zombies or rogue NPCs.
 
I would be more inclined to use traps that are essentially a harmless early warning system (e.g. a cooking pot balanced on top of door / window frame or tied to a string, which makes noise if something triggers it.

So I read that sewers will be implemented. Is it safe to say that subways, basements, cellars, and other subterrainian fare will come with that?
If so, cool.
If not, suggestion.