My understanding is that It was Stephen King's attempt at a Lovecraftian style story with an entity that shape-shifts and feeds on terror. With that said, it's not a stretch to see that It does fall into some Freudian symbolism. Especially apparent in the novel where sex is used as a rite of passage for the Loser's Club and the fact that many of the members suffer from parental torments in addition to the titular creature stalking them.

Granted, I'm not sure if this was King's intention, but death or the author and all that can make a strong argument for other meanings within the text.