Although I must confess to not quite getting the gist of The Waste Land either, having just finished Iain M. Banks' Consider Phlebas, the above explanation seems to show links between Phlebas (in the poem) and Bora Horza Gobuchul in the book.

In particular:

  1. Phlebas-- is merely a businessman interested in "profit and loss".
  2. If Phlebas is not resurrected, the wasteland remains barren and the King infertile.
  3. Phlebas has so far spent "the stages of his age and youth" in the whirlpool

These three things would seem very appropriate; his involvement in the war was essentially mercenary in nature since he didn't really agree with either side; the name Bora Horza Gobuchul is resurrected by the Mind he sought to capture and as a Changer he had spent his life as many different people, young and old.

Death by Water in itself is an appropriate reference to the passage from the book which Horza recites in his mind so many times throughout the story:

The Jinmoti of Bozlen Two kill the hereditary ritual assassins of the new Yearking's immediate family by drowning them in the tears of the Continental Empathaur in its Sadness Season