My problems with the sound effect library question:
Due Diligence and standing.
Due Diligence: you've given no evidence that you haven't done a trivial google search for sound effects.
Standing: Your question is: "Where can I find a sound library?" for a bunch of generic sounds. While these are certainly related to RPGs, they're in no way restricted to RPGs, nor inform the design of an adventure. One test for sounding: Is this just as valid on another SE site, like sci-fi? (Yes: you are asking for fantasy sounds, this is just as valid on sci-fi, therefore it lacks standing)
The artwork question is a significantly harder question in terms of due diligence, and since he's looking to structure adventures around it, has RPG standing. To be fair, I'm not especially happy with the artwork question either, but I didn't see it.