Carry That Weight adds inventory space for crafting parts, traps and throwables. It is a Tier 4 Survival skill that lets you bring more Molotovs, bombs and crafting supplies into a big fight.
Yes, especially before you start taking on large Hordes.
Green Thumb and The Butcher, since you carry more of what they give you.
Craft Molotovs and Attractor Bombs from your spare parts before a fight. That frees room and gives you more tools.