Answer:
What flares up and does a lot of good, and when it dies is just a piece of wood?
Two bodies have I, though both joined in one. The more still I stand, the quicker I run.
There is someone, and there is always another, for without the other, there wouldn't be one
Three lives have I. Gentle enough to soothe the skin. Light enough to caress the sky. Hard enough to crack rocks.
What has two spines and a lot of ribs, and carries much but never moves?
I am your mother's brother's only brother in law. Who am I?