Answer:
Autumn leaves and bad bowlers wreak havoc on this
Power enough to smash ships and crush roofs. Yet it still must fear the sun.
I cost no money to use, or conscious effort to take part of. And as far as you can see, there is nothing to me. But without me, you are dead.
When liquid splashes me, none seeps through. When I am moved a lot, liquid I spew. When I am hit, color I change. And color, I come in quite a range. What I cover is very complex, and I am very easy to flex.
What starts with a 'T', ends with a 'T', and has T in it?
You use it between your head and your toes, the more it works the thinner it grows.