This combination gives the highest possible base defence chance of 35% - when combined with Parry (+75%) this will make the player unhitable by all attacks other than special attacks.
Further, unlocking both the Elusive and Unstoppable legendary traits boosts this value up to 75% (+20% each) - which means that even a simple 1-space "Move" will make the player unhittable.
Do bear in mind though that certain enemies have attacks that are considered special attacks, eg. Headbutt. Being vulnerable also massively negates the benefits of this.
Note: status effects such as hunger, tiredness, pain can reduce your defence, making it more likely to be hit.
Keep Fed Edit
The negative trait Metabolism is unique, in that it actually boosts the player's ability to heal. However, this comes at the cost of faster food and water consumption.
Trapping and Botany both make food scavenging near-trivial, which in turn means that the negative effects of Metabolism will be felt less.
Essentially, if you were going to take trapping or botany anyway, Metabolism will make those abilities that much cheaper - especially useful for trapping which gives you the ability to make multi-functional fire.
Ruin Scavenger Plus Edit
The above combination of Traits and Items/item categories gives the largest boost to your Scavenging stat imagineable when searching ruins or buildings. Lockpicks are situation so won't come up everytime however.