1) Yes, the Druuge have the Glowing Rod, Rosy Sphere, Wimbli's trident (see below), and some other thing which I can't think of offhand. The rod is useless.
2) The second Shofixti is Tanaka's brother, Katana. The only way to find him is to "accidently" kill Tanaka. Katana will then appear in his stead.
3) The rainbow worlds roughly point to Groobridge. Had the game been "finished" you would have brought Wimbli's Trident to the system, used it, and discovered a secret.