Why was Thor going to be made king if Odin is immortal?
According to legend, the Odin Father is the keeper of the Odin Force, and must enter the Odin Sleep once a year to retain his power ... we see a pattern here that Odin is somewhat important. Additionally, some legend says that Asgard survives and maintains it's splendor specifically because of the Odin Force, which is only maintained by the will of Odin. So if he is going to always be around (for Asgard to persist per the previous legends), is Odin merely a title, or is there something more important about Odin that he will persist even if Thor replaces him? Odin does seem to be a little invincible after all.
Was the title merely hereditary and each Odin passed the title before dying or is there another reason for Odin passing the title?