Can Rainbow Servant be combined with Versatile Spellcaster and Spontaneous Divination to cast all Cleric spells spontaneously?

A ridiculous idea has occurred to me and I’m looking to verify if really works. Consider the following build:

  • Wizard 5/Rainbow Servant 10 (a class from Complete Divine)
  • At Wizard 5, take Spontaneous Divination from Complete Champion so that you qualify for Versatile Spellcaster from Races of the Dragon.
  • Take Versatile Spellcaster at some point.
  • At Rainbow Servant 10, you gain access to the entire Cleric spell list.
  • Put together, Versatile Spellcaster and Rainbow Servant 10 should let a Wizard cast spontaneously from the entire Cleric spell list.

This gives me two questions, the first as a focus and the second as a supplemental:

  1. Does this actually work? My first objection is that I’m not quite sure if the Wizard automatically knows all of the Cleric spells at Rainbow Servant 10. If you have to record them in your spellbook, you’ll soon run out of gold.
  2. If this does work, can the "powerful non-Diviner spellcaster class that can also cast spontaneously from the entire Cleric spell list" idea be done better? The term "Rainbow Warake" seems to be in my memory.