Dirk Gently (TV series)/Headscratchers

I think I need an explanation of the ending of the first book. I understand that ? And what on Earth happened to the poor bastards delivering Richard's sofa when
 * In order:
 * The sofa thing worked like this:
 * Not quite:
 * The ghost planned, not to, but to . This would have wiped out humanity, because.
 * Yes, but how would.
 * The way I see it,
 * The ghost planned, not to, but to . This would have wiped out humanity, because.
 * Yes, but how would.
 * The way I see it,
 * The way I see it,



Related, but not quite the same: I've always been bothered by the Timey-Wimey Ball aspect; are we in a Stable Time Loop (Richard's sofa suggests yes) or not (nearly everything else suggests no)?
 * Stable time loops can arise from a system allowing one to change the past.


 * Everything in the Dirk Gently series is said to be relevant. But having read it for the umpteenth time, just what eactly is the significance of the Monk and of Gordon Way's ghost?