When is it appropriate for one to integrate with OpenSea’s API directly, the QuickNode NFT API, or some other approach?

I haven’t actually played with OpenSea’s API in depth, but I do know that in some cases, it can be and we'll call it complementary to using QuickNode. If you want to know, for instance, what the description of a NFT collection is, only OpenSea has that. If the collection is a verified collection on OpenSea, or it's a verified collection on Rarible, each of them will have their own respective descriptions. That's just for them. If there's a description of a particular NFT token that lives on OpenSea or Rarible, they'll have that again, respectively. But all the data that's on chain, all of us have too because it is, by nature, public.

The picture of the metadata—who the current owner is, what its properties are, what the collection address is, what the token idea is, what blockchain it’s on, what standard it's using—are all the same across all of us. It's just those certain collections that are verified in one place or another for which we don't have that top-level description, for the most part. It really is only description as far as I could tell.