Otherwise, say the mage wants to carry a shield and a rapier, no.
I might even allow that one... but I'd point out that even in "triad" spells, where it's actually all a single action, the spellcaster suffers from splitting his attention multiple ways. So sure, if you want to cast a spell with the "point of focus" as your eye, or the tip of your nose, or whatever... yeah, you can.... but the rapier and shield aren't really any help for purposes of defense while you're doing so, you'll be counted as stunned and unable to parry for purposes of combat while you're casting it.
And you still have to commit to extra skills, like Spell Mastery, in order to get even that much.