Probably the two best feats are Cold Fusion (which is equivalent to wearing another heavy coat at all times, for no Mending upkeep or Weight) which helps in the early game a ton, and late game as well (particularly on Stalker and Interloper, where the world gets noticeably colder over time, or allowing lighter clothes to be worn); and Efficient Machine which is better than '10% more calories from food', in that it reduces all food consumption, making the Early/Mid game easier, their transition smoother, but also the Endgame occur sooner and more powerfully, particularly with more time spent "hibernating" with less food, less starvation overall, and every food item/animal carcass giving far more range of coverage between meals.
Expert Trapper is arguably the best 'ultra-late game' Trait, once all Rifle/Revolver Ammunition is spent (including crafted ammo) and all Arrows broken (minus the rare Saplings found Beachcombing). At this stage of the game, Calories can only be acquired by: Stoning Rabbits (limited availability, due to depletion), Snaring Rabbits (normally inefficient), Steering Deer/Rabbits into Wolves and scaring the Wolves from their Kill (slow, tedious, slightly risky), Killing Wolves in/after Struggles (extremely high risk), and Beachcombing (slow, limited, RNG heavy). Snaring Rabbits is normally a minor supplemental income at best, and a slow way to starve at worst, particularly on Stalker and Interloper, but double effectiveness for snares gives far, far more food and makes them viable calorie farming especially when accessing 3+ Groves in close proximity.
Fire Master's no tinder is cute but the +firestarting chance is a solid early-mid game choice particularly for Interloper playthroughs, because of the shortage of Matches. However, because it is relatively easy to spam Campfires via Torch+Stick spam to skill up Firestarting, and because Magnifying Glasses are an item, this Feat gets dramatically worse the longer the game goes on.
Free Runner and Snow Walker are a great combo together for more and cheaper Sprinting, however they strongly de-incentivize wearing bulky clothing (like Ski Boots, or most Crafted Animal Clothes), and even with both Feats, Sprinting regularly will lead to exhaustion and wasted calories.
Blizzard Walker is nice when relevant, but not relevant often since it has no benefit when not walking directly into wind, which is normally easy to partially mitigate by moving diagonally into the wind. This would be useful for Challenges, Wintermute, and Speedruns to help mitigate Wind RNG, but it cannot be selected for those modes.
Straight To The Heart is similarly terrible in Survival to Book Smarts in that it has extremely limited use: since Coffee, Energy Drinks, and Stims are a finite resource in the world. Of note, this Feat does not increase the Fatigue restoration effect from Coffee/Drinks or the Condition restored by Stims, merely makes their effects last 25% longer (reduced Fatigue consumption for Coffee/Drink, more time with infinite Fatigue with Stims). If this feat was "100%" more effective instead of "25%", it would still be a questionable pick, but would be more reasonably in-tune with other Traits, or would be a better pick if any of these 3 items were renewable somehow. However if Feats could be used during Challenges, Wintermute, and similar 'Speedruns', this would by far be the best for those settings, since Coffee is so valuable there, but alas they cannot and it cannot. Strangely, this Trait also does nothing for Herbal Tea.
Book Smarts is miserable, horrible, putrid. Clearly the worst Feat in the game, by far. 10% more benefit means from a Skill Book which gives 10 skill points... Gives 11 instead. Books are quite rare, finite, of limited short-term benefit as eventually all skills will get maxed (except Rifle and Revolver on Interloper...), so this perk is not only extremely unimpactful but also gets dramatically worse the longer the playthrough goes on until becoming completely pointless.