Hmm, perplexing. So you have to will the magic into existence and realise that it won't hurt you whilst ignoring your common sense. That Breathing Water book was interesting, he had to concentrate on his spell to make sure he didn't drown. However, as soon as he forgot about the spell and reality took over, he failed. It seems like enforcing your own reality through willpower is the name of the game in Alteration. That certainly explains the use of willpower in magic- enforcing your whim on reality. Unfortunately, it doesn't explain Intelligence's role- if it even has one.
O.T- Astion was that quote from Mythbusters by any chance?
It makes sense when applied to the college of Destruction, another college that is governed by Willpower. Wizard A hurls a fireball at Wizard B. Wizard A knows the fireball won't burn his hands because he summoned it and the magick is under his control. Wizard B doesn't have that advantage. If his willpower is strong enough, he may be able to negate the effects of the spell, sort of like a Yogi coalwalker. If it isn't, he ends up as a mound of charred flesh.
There might very well be a component of Illusion to Destruction magick... and in fact, there probably is. Perhaps it is better to say that the colleges of Destruction and Illusion are components of a greater, more universal system, seeing as the colleges were an invention of Galerion's that simplified magick use for the greater population. The Psijics of Artaeum, of whom Galerion was a member, had no such distinctions between "colleges" of magick. To them, practice of magick is known as "http://www.imperial-library.info/obbooks/old_ways.shtml", and involves subtle interactions between the physical and spirituals worlds.
Intelligence plays no role in Alteration, Restoration or Destruction. Intelligence governs Mysticism and Conjuration. This might seem counterintuitive, though, since Mysticism is... well... mystical, and would ostensibly involve feats of will rather than of intellect. However, I have always likened mystics and the more esoteric mages in Tamriel to theoretical physicists, because of the http://www.imperial-library.info/mwbooks/benitah.shtml and because of my own aesthetic bent. They have to be familiar with the way that the Aurbis works - how the realms stand in relation to one another. They have to conceptualise rather complex things, such as imperceivable dimensions and bridges between the realms (Wormholes, anyone?). On some level, it is possible to show
theoretically that nothing in the Aurbis is separate from anything else, and that the Aurbis doesn't really exist. If you can do this on a purely theoretical basis, you can manipulate the fabric of space and time without worrying about spontaneously evaporating.
As for the quote, it was, indeed. Although I'm not sure whether Adam got it from somewhere else or not.