If its 2 points of Focus Fire on an opponent for example, that means your units would force themselves to attack that unit. However if all opposing units would have Focus Fire marks then it would be the normal targeting mode. Its an additional 1% damage per FF point, and there are some generals who have skills in relation to FF.
Use the jade ticket, because it's an automatic UR. You don't wanna sacrifice that UR even if it's not Platinum Priest event right? XD