Ok, some people will say "Ah! This game is simple, you need only click action icons!" ...

Ahaha... Very simple indeed, except that there's a lot of things that you don't know what they are and you cannot know every possibilities about this game!

For example, what is the use of the icon near the bandage and medicine ones?... What is its use?... I don't know!
Is it possible to feed someone who is sad and can't move or to heal him/her?...

How you know to go in garden and plant some stuffs to farm food?

How to barricade house, etc etc... There's so much questions where you can't have answers!!!

Would be nice yes, but you can always google when you can't rtfm.

I found barricades (upgrade workbench) but other than that some doc would be welcome...

To answer one of your other questions, the medicine cabinet icons are for bandages, meds, and herbal meds.

Agreed, no manual is a dumb thing to do. Come on 11bit, really?

Sure, some things are easy to figure out, some are a bit harder but some are virtually impossible to find out exactly. All you can do is wild guessing. For example the morale system is a complete enigma. Also, can you heal "slightly wounded" or "slightly sick" without bandages or medicines? The doctors in the hospital say you're fine but in my experience if you don't treat those statuses they'll get worse and never heal just naturally.

Also some of the character abilities is a mystery. So Boris is "strong" and can carry a lot of stuff. But does it apply to his combat effectiveness as well? And what exactly "Trained in Combat" means? And how does "Bolsters Spirits" work? What about "Loves Children", "Good Mathematician" or "Lawyer" - are those just useless, dead weight characters? No explanation, no numbers, no percentages, no nothing. Bad developer, very naughty!

More damage in head-to-head combat (read somewhere about a 20% increase); can do stealth kills from behind (at least on unarmored enemies) with weapons (knife & crowbar confirmed; possibly hatchet and maybe the shovel but I wouldn't count on it); better at guarding the shelter compared to others, although this is unconfirmed as of yet When someone's depressed, they're more likely to pull them out of it when talking to them; can play the guitar really well and this uplifts sad characters in the long run Nothing is confirmed, but there are speculations that "Loves children" = more susceptible to mood changes, both good and bad. i.e. help the kids who ask for medicine, and she'll become instantly content. Go tell them to go fuck themselves -> depressed status. "Good Mathematician" = again, this is only speculation, but some think he's better with traps (gets results faster); personally, I doubt this. "Lawyer" = well, no one really knows for sure. It is entirely possible all of these are characters with no visible, helpful traits, thus "dead weight" as you call them (they can still help you with tasks, you know)

Yeah, I suspected most of this, but as you write yourself most of it is just guessing or unconfirmed.

That's usually fine, I don't mind discovering stuff for myself, problem is how can you ever confirm things like "being better at trapping" when trapping is chance based for everybody so you can never separated the bonus chance from just normal luck? Similarly, many mood-related mechanics are virtually unconfirmable too.

Also, Zlata can play the guitar - so do I have to actually play it or do I just have to repair the broken guitar, place it somewhere and forget it? Coz I had her play the damn song all day long, two days straight, but nobody was cured from the "Sad" condition. Plus I didn't notice she's more successful at consoling anyone when depressed or broken (come to think of it, I don't think I've ever succeeded at curing those conditions with anybody, just wasted a lot of time; alcohol usually helps but then the characters are drunk and hungover for two days).

Zlata does not cure "sad," but she can talk to characters that are depressed and remove the depressed status. It makes a new icon over their head if you have her and a depressed character. Depressed characters are at risk of killing themselves, so it's a useful skill to have on your team.

I think the spirit of discovery is part of the enjoyment of the game personally. Even misclick combat deaths (my biggest problem) simulate modern combat when you think about it :P

How do you know that? Any source on this? Because I've done about 7 playthroughs and I haven't noticed anyone being better at consoling others than anyone else. How can you possibly test if Zlata is more successful if her chance to "cure" depression is, say, 10 % higher? You'd need an inordinate amount of playthroughs and tests to confirm that.

And what about that guitar? How does that work? And coffee or cigarettes? It seems if I ignore that my characters go "sad" (again, hard to confirm) but what does it mean? I haven't noticed any significant change between the normal - sad - content state of mind.

Sigh, as I said, I love exploration and figuring stuff on my on but for some things you just need at least some basic explanation.

Who says I need a source besides myself? Whenever I've had really hungry people, really depressed, sick or hurt people and I select someone besides that person Icons will appear above their head. If you click on one of those icons, the person you have selected will act accordingly to the situation. If someone is especially depressed, another person can console them or at least try to if you click on them, then click on the speech bubble above the depressed person. I wouldn't have a damn clue if Zlata is better at it or not, I'm just going by her 'bolsters spirits' trait. Keep in my that other factors around the house could play a part too, such as how the living conditions are. You won't see parameters skyrocket from one little chat between people for crying out loud.

You don't have to believe me and I'm sure as hell not trying to persuade anything from your sceptical self; I'm just telling you how it has been on my many playthroughs.

I agree no manual was rather odd. Most of it is self explanatory but there are lots of questions people have me being one of them. I guess 11bit studios are trying to immerse everyone in the ethos of the game where in such a situation, you don't know what is going on.

Correct. IIRC the developers pretty much said they didn't give players a manual because you don't get a manual when war comes to your doorstep. Keeping game mechanics hidden, with no documentation, is intentional.

Agreed.
But also all the more need for sandbox so you can experiment with stuff after beating it. I managed to survive to day 45 but I would like to try out some of the other functions without having to play 6 hours to get some parts, so it is a little frustrating now.