Bush crafting:

You can craft 3 types of shelter: tarp, leather, and improvised
So you just always build the fantastic improvised one. It's a no-brainer if you want to hide it in the woods. You don't even have to go looting. All items in its recipe are craftable.
Rope, sticks, long sticks.

But why not differentiate the shelters by size and damage?

Tarp shelter: Most hit points and inventory space
Leather shelter: Mid-size hit points and inventory space, but craftable without looting
Improvised shelter: small inventory space and hit points, but craftable without looting and perfect camouflage

Animals:

Chicken and rabbit should have "small guts" when gutted (f. e. important for crafting a rope)

Gear:

• Improvised Bow and Recurve Bow

The models are in the game... Apparently no big deal since the game has a simulation for arrows?

• Advanced Improvised Bone Knife and Stone Knife

It looks like you need rope and bones - but the crafting is done by 2 bones or a bone and a small stone. It has magically rope on it. Not plausible!
What about 2 stages of crafting (like the improvised arrows)? The "improvised bone knife" with lower durability and the "advanced bone knife" with better durability.
Differentiation: Stone more durable than bone.

Step 1:
bones + bones = improvised bone knife (new model without rope on the model)
or
bones + stone = improvised bone knife (new model without rope on the model)

Step 2:
improvised bone knife + rope = advanced bone knife (existing model in the game)

Same would be needed for the stone knife.

Step 1:
small stone + small stone= improvised stone knife (existing model in the game)
or
stone + small stone = improvised stone knife (existing model in the game)

Step 2:
improvised stone knife + rope = advanced stone knife (new model with rope on the model)

This would made the stone spear more plausible. Right now the stone spear model has rope on it.

• Bone Spear and Stone Spear

Spears are now more or less useless ingame. How about actual throwable spears? Differentiation: Stone spear more durable than the bone spear.

advanced bone knife + long stick = bone spear

advanced stone knife + long stick = stone spear

Clothes:

More items should be craftable with tanned leather. For differentiation between civilian and military clothes, the leather clothing should be more durable against infected attacks.

• Leather gloves
• Leather hat
• Leather pants
• Leather shoes
• Leather jacket
• Leather shirt
• Leather storage vest
• Leather knife sheath
• Leather belt (model is not finished)
• Leather water pouch

All in the game files. Even so, most of them have 4 colors: natural, beige, black, and brown.

The coloring of the leather would be appreciated. But it would make things more complex, too. It would require adjusting the coloring a lot. Some colors of tanned leather items mismatch and some have no color variants (shirt, shelter, knife sheath, water pouch). Maybe it's a task for a future update.

With these changes, you can live a life as a real "hunter," living off the land with gear you could craft.