Have I got the basics of Evolution Theory correct?

It is as good as any other. Evolution is a pot of crock, so you might as well go with this one. If you have a panel of say 10 evolutionist scientists, and ask them to give the basic theory of evolution you will get 410 different theories. That is the rule of evolution. It changes every 6 seconds and nobody can agree on the right one, not even evolutionists.