Hey Justin, your equipment is great, but it sounds like you have your bindings canted inward? And no toe lift or heel lift? If so I think you should try removing the cants and putting an F2 lift kit under the toe of your front binding and another under the heel of your back binding. This stance is more stable, comfortable, and powerful. Try it and if you feel you need to add one or both cants back in, that's fine, but toe and heel lift are important. The bindings come with one lift kit. Order another from Donek. If you only have one and you're going to ride/race before the new one arrives, put it under the toe of your front foot. The boots have significant ramp angle built-in due to the design of the heel, so you want to cancel some of that out on the front foot.
Perhaps you need to detune the edge near the contact points? That 179 is a great board for that course. Also, not sure how much freecarving you are doing but definitely practice outside the course in your free time as much as you can with your race gear. The more familiar with it and in command of it you are, the better you will be in the course. As for the plate, I've moved on to Allflex for GS and honestly I can see why all the world cup racers use them. If you put your Apex back on and you like it for freecarving better than without, then it would probably help you in the course. If not, then don't bother.
Pretty sure I will be back in the Pleasant Mt. beer league next year.