By the time you finish adding restrictions it won't be the same ability any more.
Perhaps. But without any restrictions, I fear it may be "OMGz BORKEN!1!"
You might as well let him do something very specific as a free action once per round. Or make it use his regular quickcast without giving him an extra one. If he wants another spell action he can summon a spawnpoint or familiar, after all.
Not sure I understand what you mean. The ability itself wouldn't grant any additional actions, just allow you to use your quickcast like revealing an enchantment... which would be very powerful.
The ring I suggested would be a way to sacrifice your regular action (potentially after moving, possibly even moving twice via Cheetah Speed) in order to get a second quickcast in order to use the above ability twice in a round. It isn't required for the ability, but just lets you exploit it even more if you want. The ring would need to be priced accordingly: probably 2 or 3 mana, given that it comes with a drawback (e.g. uses your regular main action, so no casting a full-action spell that round, aside from any spawnpoint/familiar you might have).
Or perhaps there might be another equipment: the hourglass itself might take up a weapon/shield slot, and allows you to flip up your quickcast marker after your mage takes an action (e.g. same timing window as Dancing Scimitar's attack). This would have to cost more, though, since it gives you an extra quick action per turn, and a powerful one at that given the proposed mage ability above. And you'd pretty much need either a wand or the Tome (or make a melee attack, or guard, or double-move) in order to get maximum use out of it, since it doesn't let you prepare an extra spell.
By the way, a simple use for this ability is Battle Fury. There have been times (mainly in Domination) where I've quick-casted Battle Fury on a friendly creature, then activated that creature and rolled above average, killing its target with the first swing... which means I completely wasted the 5 mana and quickcast spent on Battle Fury! With this mage ability, you could attack with your creature, then after the "apply damage & effects step", choose to quickcast Battle Fury, then take a second attack with your creature if and only if the first attack wasn't sufficient to kill the target! That's not nearly the most powerful thing this ability could do, but helps demonstrate its flexibility, even if it were restricted to Incantations. Similarly, you could Minor Heal a friendly creature after the roll dice step of an enemy creature targeting it, to prevent its death on demand. So many possibilities!
