Must admit, I've not seen either of those... never have cared to, particularly. Have only seen parts of Escape from LA...
Well, the Hob's End would also, I'd think, be a reference to Quatermass and the Pit, part of which has such a setting (though not a town, but a setting with that name). I wasn't aware that he thought of this as part of a trilogy, and I must say I don't see the connection between this and The Thing at all; I'd like to hear more of his thoughts on that one.
Some of it is intended as humorous -- the scene with the painting is, I think, meant to be both grotesque and humorous, as well as disturbing because it's humorous -- a bit of Bierce there, perhaps. It's also a reference to Richard Upton Pickman, from HPL's "Pickman's Model" ... the whole film is an homage to HPL, varying between being full of references and in-jokes, and also with Carpenter's own take on some Lovecraftian themes (the blurring of boundaries between reality/dream/insanity, for example).
I think I find it interesting for those reasons. It's a flawed film and, as I said, I don't think it holds up as well on repeated viewings (for me)... but it still has an air to it that I quite like.....