Chargeable actions is an awesome idea! There should be a limit to how many times you can charge though, maybe with a timer or some sort of point system. Such as, every 25 seconds you gain a "point" that can be used to charge a spell or ability. Higher rank spells or abilities would require more points for you to charge them. After you charge an action you lose the points you have accumlated and cannot charge again until you have sufficient points to do so. Just a thought. Love the idea though.