Off the cuff, I agree with others that Second Nature seems considerably powerful, especially as broad as it is.
Perhaps, make Second Nature like some other Talents like Knowledge Specialization and Smooth Talker (yes I know they are skill related) and have the player choose a specific Talent they wish to be second nature?
Or possibly, make it like a Natural Talent, letting them choose any one skill and possibly drop the improved version.
Just random thoughts from my group while we break for food. 🤷♂️
Edited by Jareth Valar