Everything I have learnt about d&d (and pathfinder is d&d) wizards makes it sound like the most boring class of all time no matter how "powerful" it is.
A necromancer who does not possess the necromancer class is... a rather curious concept, but strange enough for a pathfinder-like setting.- A lot of the more long-term effects, like creating undead or summoning/binding outsiders or plane shifting or, hell, even Wish and Resurrection... aren't spells any more. They're rituals, and as such can be learned and used by anyone, even non-spellcasters, and depend on the use of skill checks.