Illnesses are more likely to happen to those in poor health. The immunities are especially noteworthy. They increase the duration of alcohol/chems, give you immunity to addictions, and can raise your luck (Party Boy/Girl). Party Boy/Party Girl, Chemist, Chem Resistant: If you aren't adverse to using alcohol/chems, these would be useful.Depending on how you play, this might not be worth it. Moreover, it seems the rate at which your hunger rises is greatly increased, forcing you to seek out more cannibal victims until the debuff is removed (by sleeping a long time, 24 hours seems to do the trick). Cannibalizing an enemy will give you the Dark Craving debuff, which allows you to only eat human flesh (no standard food) to recover health and hunger. However, this seems to come at a steep cost, according to this answer. Cannibalizing a fallen enemy will also recover some of your hunger. Save Stimpaks/food, no need to wait for the slow recovery. Cannibal: You can eat humans, ghouls, or super mutants for an immediate, decent health boost.This can also assist in healing quicker to counteract the slowed recovery from food/Stimpaks. You don't have to worry about the ill effects of RadAways if you don't have to use them. It can save you from using some Stimpaks, and prevent you from needing RadAways in many cases. The second point reduces rads in the sunlight, the third recovers health. Solar Powered: Even though this is at 10 endurance, it can be simply great for maintaining health.Depending on which DLCs you have installed, you may have a better way to manage radiation long-term (such as the Decontamination Arch offered in the Wasteland Workshop DLC), but resisting extra radiation in the field can still be useful, especially if you're spending some time in the Glowing Sea or fighting Children of Atom with Gamma Guns. Rad Resistant: The less rads you take, the better, due to the negative effects of RadAways.Keeping rads as low as possible is more urgent now, as RadAways now add fatigue and an increased risk of illness by using them, so they need to be used more calculatedly. Lead Belly: Since you need to keep hydrated, it might not be a bad idea to pick up Lead Belly.Being over-encumbered can also cripple your legs. Limbs now require a Stimpak to be healed, even outside of battle. Adamantium Skeleton: Limb damage seems to be more of an issue.Toughness and Refractor increase damage resistances, Lifegiver for +60 health and slow health regeneration (at rank 3). These might give you that little extra needed to survive. Since saving is pretty much strictly tied to using a bed, loss of progress is a real threat, especially due to the big increase in damage taken. Toughness, Refractor, and Lifegiver: On top of Endurance giving you more overall health, many of its perks increase your survivability in the Commonwealth.On top of the ones you've listed (Strong Back and Local Leader): As the mode name implies, survivability is much more difficult, and can lead to loss of progress due to not being able to save at will. Many other perks have become much more useful with the changes in the new survival mode, especially in the endurance tree.

Fallout 4 perk chart chemist