To add a little quirk to the mix, if you are casting out of scene, or even in a low pressure point in a scene (traveling the hour to an encounter, say) how does, "Focused on the task at hand" (pg 136) apply to spell casting? It is a skill role and if it can ever be applied to spell casting it should apply at those times. (And by the rules it seems like it could be applied to spell casting) That would seem to increase the average roll on a spell outside of combat.

I do not think that spellcasting outside of combat should default to the passive value of the caster for this reason and because other bonus's (prodigy, runes, etc) don't effect your passive value. I could easily see saying you can cast spells outside of combat at your passive +3 or something of that nature, to reflect these other effects on your average casting role, however.