Hmmm. I think rather than using stuff like that I'm going to take a page from the water arrows guy and make spells that disable lights instead. Light and darkness seems to be one of the biggest factors for detection anyhow. Other than sound, but muffle already exists.
Yep. dark/light has a big effect .... if you can come up with a plausible way to make it go dark - when the player needs it - that's the easiest way to make sneaking easier (useless your player is out hunting in broad daylight!

).
Muffle is also very good ... there's a set of nightingale boots that have everything you need (though the scripting is easy, anyway). And works in the daylight!

But all of that other stuff in the Detection-article is also useful ... how firing weapons and similiar effects NPC state ... just so you know why your prey-herd goes all alert when you kill one of them etc.