Here is a list of all the amphibians that can be found in Colorado:
List of amphibians of Colorado - Wikipedia, the free encyclopedia
It *can* be harmful to handle these toads, but it really depends on how clean your hands are. It's usually recommended to wash your hands thoroughly before handling amphibians. However, when these toads are in the wild they are exposed to many different elements...so unless you were handling something toxic it probably didn't impact the toad too much.
Toads can eat many different things. At a young age, I'm guessing he probably ate small insects. He could become snake food, but that is true of all toads and frogs. I just try to not think about it.