You've ruled out pretty much all the big ones. MMORPGs with deep PvE gameplay and tolerant combat systems. Many, maybe most, new MMOs are introducing more active combat systems.
You could try Tera, but it is one of those modern MMOs with action combat. It does have reasonably challenging PvE, but no raids.
You could try a popular single player like Dark Souls and Skyrim, of course.
On further thought, even if you do not like "shooters", maybe your best bet is Fallout 3. That certainly has depth and its no ordinary high octane shooter at all.