character perks help?

[zettafab]

i'm very new to this all, i just created my first custom don't starve character.
I want him to lose sanity faster, transform when his sanity is low enough (appearance change + hits harder), and start fires when low on sanity.

i know for the last one i should be able to just take the code from willow, but i'm not sure...what exactly to take, or where to put it. and for the other two i really just have no clue what to do haha.

help a dummy out? ;v;