Welcome to WWGHA, Ellie.
You put some effort into your post, although nobody has posted in it for 5 years. Normally, I would ask you to start your own new thread but this is your first post and the question is the most basic question of the site.
As I understand it, you suggest that because we are bad there are amputees whom God will not heal.
However, Jesus was there well after Creation, yet he did heal people. He healed the deaf, the blind, the lame, those who were suffering from demonic possession, but he never healed an amputee.
Today, people claim that a godly miracle cured them of something, but an amputee has never claimed this.
So we have a world in which God heals many afflictions but cannot cause a lost arm to re-grow. God can make a universe and all life on it, He made insects, crabs, and lizards who can all re-grow limbs. But, for us, made in His Image... well, He seems to do nothing. He does not help.
So it cannot be just "sin" can it?
Why do you think that God hates amputees and refuses to help them?