You've set yourself a herculean task. Just trying to remain consistent within one fictional setting (even if fanficdom has expanded the Harry Potter Uni beyond all recognition), is difficult. By drawing on WOT, Conan and the rest? OMG, the mind boggles.
That said, just write the story (soonest! hint! hint!) the way you want it, and ignore the fanatics of any that say it doesn't work that way. You've hit a sweet spot with your lemons as well, just enough detail to make it hot, not so much as to make it labored.