These are probably a dime a dozen, but I want to throw my hat in the ring too.
So Wilson should be vanilla and easy to survive with? How about:
- Grows a magnificent beard (the same)
- Loves science (double sanity from prototypes, maaaybe a decent sanity regen when near science machine/alchemy engine)
- Enters the constant with: 5 twigs, 3 flint (enough to make the 2 basic tools right off the bat and later a torch)
Maybe small enough to remain the default character, and "good" enough to have a noticeable upside and some niche applications, without trivialising any important part of the game.