Headscratchers / Buffy the Vampire Slayer S2E19 "I Only Have Eyes for You"

• Why are James Stanley and Grace Newman unfortunately stuck on a loop? Why do they possess people to re-enact the final acts although they can't die as ghosts? Are they still already dead? Is it because Hellmouth warped reality and casted a spell on them to trap them in a loop?
  • For the same reason that they're ghosts at all: unfinished business.
• Grace, in Angel's body, is able to talk James out of killing himself, in Buffy's body, ultimately allowing them to break the cycle and move on. This implies they do have some agency over what's going on and, going by Grace's "last breath" comment, are even aware that they are ghosts. Because of this, why hasn't Grace attempted to reconcile with James before? Alternatively, why is whatever evil magic or Hellmouth manipulation that was forcing them to replay their deaths no longer in effect? Even if Grace wasn't compelled to "play dead" in Angel's body, why is James no longer forced to kill his host body? He didn't seem to have any control over the situation before but suddenly does.
  • The loop restarts when the James-possessed person kills the Grace-possessed person, then commits suicide. This time Grace is possessing a vampire and so can't be killed by a bullet, so she has the time to say the things she couldn't say before, being dead and all.