Two things come to mind;
The distribution of special wizard types; several people were normal boring old wizards. Considering the large number of different types this seems really silly. Furthermore i noticed we had a bit of stacking going on, there was like what, 2, 3 Archmages? It would probably work alot better if stacking like that was minimised.
Secondly, Dark magic. There's really no reason to pick it; you lose the weakness true, but you also lose the ability to get +4's from certain assists that align with your stat (which is pretty major, since the Cabal know each other's alignments and thus can line up their assists properly) and you lose the 1 in 4 chance that your enemy will do half damage. So basically if you choose Dark magic you're giving up 2 strengths and a weakness for zilch. Furthermore if you do choose Dark then you're twice as likely to be uncovered (as not only can the Justicar find you, but the Seer can too). So if you choose Dark magic you give up 2 strengths and a weakness, and then gain a whole new weakness! The choice is clearly inferior.
It doesn't need much, but i think if somone picks Dark magic they should be able to then pick an element that their Dark magic will mimic. If the seer uses his action on them then he 'sees' the mimiced alignment, not the Dark one.
If you get the role mixes down properly and give the Cabal a decent incentive to go Dark (cause right now they really don't have one) it should work much better. It was also good fun, although jumping in halfway only to discover i was Cabal was, uh, fun.