Well, I'm not sure about the dog crap...
I'm pretty sure both Square *and* Nintendo realize that releasing a game that requires 3 friends and an extra $280 or $400 investment wouldn't sell well at all. So I'd assume there most definitely would be a way to play, at the very least, 1 player w/o a gameboy (as there's no reason to hide stats then).
That said, the Secret of Mana game that made it out in the US had a very elegant menu system that never obscured the gamefield and still had a wide variety of items available. It wouldn't surprise me if FF:CC used a system similar to rings in order to keep the screen uncluttered and to keep down on programming time.
That likely means that there aren't a million different items that all do slightly similar things, but rather a few key items used for specific purposes. I personally liked the SoM way of dealing with items. Especially since most of the items in Final Fantasy games accumulate simply because you get better items but think that maybe you'll find a use for that old item because it has some special power until you beat the game and find that you just never used it again after all. I like Golden Sun's approach to items -- small items can be grouped up to 30, and large items are separate, and each player can hold a set amount. It makes you really think about what you want to keep and where you want to keep it. And it's certainly a bit more realistic...