by GI Joe
The confusion stems from the language being misused.People sometimes say "full action" when they really mean "action phase."
Your Mage, on his action phase, can either move and do a quick action, or use the entire phase to do a full action. Actions can be spells cast or attacks made, etc.
The quickcast is a separate action that only the mags can do, is always a spell cast, and is always a quick action spell. This can be done before the action phase, after the action phase, or during the action phase.
So yes, all of Brendan's options work, allowing the Mage many opportunities to cast two spells in succession, using the quickcast action.