Ha, funny joke. Because the engine doesn't have everything to do with every other part of the game, it's only the base that the entire game stands on. /sarcasm
Yes, just like the case of my computer requires specific components! It's what everything is mounted in!
No, the engine has nothing to do with the resources. It loads and uses them, they have to be in a format it understands, but that's /it/. If bethesda want to reuse resources that would be trivial.
There's a reason we have file formats, rather than everything being propriety blobs of data - so that the specific workings of what's reading the file doesn't affect it. I'm sure it's easier to be sarcastic than to have the faintest inkling of a clue what you're talking about, though.