(I'm talking exclusively about the film here,)
The Gods are mentioned a lot, but they aren't present in any form beyond statues, gifts and followers; Hector goes as far as to say he saw Achilles' men sack the temple of Apollo and the God did nothing.
Yes that is what I thought. I did not say it well before no doubt, but i meant that probably during the battle of Troy and the other classic Greek stories there were no interventionist gods in the way that the stories recorded them (you think!), rather Homer or whoever was describing events and making them into a poem would typically put the gods in to explain bits that he couldn't or simply to embellish the story and make the boring bits more exciting. And so this film is kinda like Homer with the magic stuff removed, you could sort of say that it is a stab at creating what really happened and went on to inspire Homer to create an enhanced, magical version.
So it is an approach that makes a lot of sense and which provides a way to tackle the story in a more realistic fashion while staying true to the spirit of the story as we know and love it. So, for example Achilles was just a really hard bastard who could defeat anyone or even loads of people at once, to such an extent that he appeared invincible. And so on. So I can't quibble with that approach or the rationale behind it.... but I personally just love the stories as I first read them and when i was little I really enjoyed Clash of the Titans and Jason and the Argonauts and so I wished that that magic and the gods were there.
Achilles' battle is with himself. He easily beats everyone he comes up against, but spends big chunks of the film refusing to fight because of various personal issues and friction with Agamemnon; Paris ends up killing him because he's distracted trying to find Briseis.
Though certainly it makes Achilles himself a much more interesting character. It's pretty much always a weakness in a film if the hero is too powerful so removing his invincibility is good for his story line. I don't think I made it to the point where Achilles died but in Homer's version, if I remember correctly, he was killed by Paris who was told by one of the gods (Hera perhaps) that he was vulnerable in the heel and so Paris shot him there with an arrow - I can't remember if it was poisoned or if he was simply vulnerable to any minor injury in that one place.
How did Paris kill him in the film??
You're right about Odysseus. He's barely in it. He narrates the opening and closing, has a few conversations with Achilles and you see a few glimpses of him in some of the battles and the moment he comes up with the idea for the horse, but he must have about ten minutes of screen time, if that.
Brad Pitt was the star I suppose so Achilles had to be the main guy- When I was little I loved Odysseus cos he was the smartest of the heroes, at first I always imagined him as a total weakling who needed to be twice as smart as everyone else just to survive, but of course I that was a total misunderstanding, from later events - stringing the bow that no-one else could, throwing the discuss further than ever before - it becomes clear that he is superhuman like all the other heroes (maybe not quite so much so as Achilles) and his brains are just a bonus.