1) SH2 is one of my favorite games. The graphics don't really matter to me, tbh, because it's more about the atmosphere they create than how dated they are, and they create one fuck of an atmosphere. Hell, SH1, with it's terrible PS1 graphics still scared the fuck out of me on a regular basis.
2) And Metroid games don't? lol, I don't think there's much backtracking at all in SH2, at least no mandatory backtracking.
3) SH2 has one of the best game atmospheres ever. It really started to get to me in the Hospital, but I don't know if you got that far. Further on in the game at the Historical Society through the Prison and the Labyrinth, man, I tried playing all three parts in one sitting, and by the end I was nearly shaking with anxiety and felt a little sick. Seriously, that game really gets to my after a while. If it doesn't do anything for you, then there's not much I can really say; it's just not for you.
I'd say try SH3. That game has a much more aggressive atmosphere and much better graphics, but it's a lot shorter. Also, if you're a stickler for story continuity, then you might actually want to play SH1 first.