Dynamic traits:
Trait "Sneaky" can be obtained at level 4 Sneaking (6 when starting with the "Conspicuous " trait)
Trait "Lightfooted" can be obtained at level 4 Lightfooted (6 when starting with the "Clumsy" trait)
Trait "Nimble" can be obtained at level 4 Nimble
Trait "Marathon Runner" can be obtained at level 8 Sprinting and 9 Fitness (cannot be obtained when starting with the "Sore Legs" trait)
Trait "Relentless" can be obtained at level 8 Strength and 8 Nimble
Trait "Between the Shadows" can be obtained at level 8 Sneaking and 8 Lightfooted.
Trait "Forager" can be obtained at level 6 Foraging
Trait "Trapper" can be obtained at level 4 Trapping
Trait "Scullion" can be obtained at level 4 Cooking
Trait "Electrical-technician" can be obtained at level 5 Electrical
Trait "Auto Mechanic" can be obtained at level 5 Mechanics
Trait "Carpenter" can be obtained at level 5 Carpentry
Trait "Metalwelder" can be obtained at level 5 Metalworking
Trait "Durability" can be obtained at level 6 Maintenance
Trait "Stabber" can be obtained at level 4 Short Blade
Trait "Swordsman" can be obtained at level 5 Long Blade
Trait "Crusher" can be obtained at level 4 Short. Blunt
Trait "Cutter" can be obtained at level 5 Axes
Trait "Lancer" can be obtained at level 6 Spears
Trait "Shooter" can be obtained at level 6 Aiming and 4 Reloading
Trait "Sniper" can be obtained at level 9 Aiming (cannot be obtained when starting with the "Short Sighted" trait)

You cannot lose or obtain next traits:
Strong Back
Weakly Bleeding Wounds
Mushroom Picker
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Lark
Owl
Weak Back
Sensitive Digestion
Heavily Bleeding Wounds
Weather Sensitive
Allergic
Panic Attacks
Sore Legs (but pain gain decreased with Running skill and have 50% maximum of basic pain amount at max Running level)
-
Slack and Taut just changing starting points of Strength and Fitness and does not affect your further gameplay. So losing it or obtain have no sense.