I would say, most emphatically, that you are missing a great deal by skipping Se7en. But I accept some people don't like horror, and this is a disturbing film. When I first saw this in the cinema during the original run, I needed a stiff whisky afterwards. Then again, I relish the masochistic catharsis that comes from watching films that scar. :)
It is also a brilliant film for many other reasons - astonishing direction that proved massively influential, superb performances, and a first-rate screenplay, for starters. The characters are important, and I'll get into that more if I ever write an article about this film.