Answer:
The more you take away from me the bigger I shall get.
I have a little pool with two layers of wall around it. One white and soft and the other dark and hard. What am I?
Die without me, never thank me. Walk right through me, never feel me. What am I?
You can read me both ways I wear; One way it's a number reversed a snare.
Who makes it, has no need of it. Who buys it, has no use for it. Who uses it, can't see it. What is it?
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.