He's *a* god. Christianity pretends to be monotheistic but has many deities with divine powers present in the gods of other religions. Jesus, Yahweh, Elohim, Satan, various demons, various saints, various angels, etc. They're all the gods of Christianity.
Not really. A god sits at the top. Jesus is just one manifestation of "the" God. Like the trunk of an elephant or the roots of a tree. We're small, so we generally see His attributes as their independent branches.