Firstly, please give me the contact details of Earwolf's lawyers, as I may need to sue for involuntary head injuries caused during the argument about the fucking aspirin bottles.
Secondly, yes, Seven belongs in the Canon, although I do feel that time has diminished it somewhat - due to its nature, it's a film that works best the first time you see it.
Thirdly, I've always considered Seven to be a semi-remake of The Abominable Doctor Phibes. Both feature a madman embarking on a biblical-themed murder spree, and both end with the killer using himself as the final "victim" of his own scheme. In fact, was Dr Phibes the first ever "themed killing spree" movie? It feels like it was.