You can omit the honey as it's high in sugar and use the artificial stuff instead, but I thought you'd want to keep it natural. Isn't maple syrup just as high in sugar? Also, do use the real stuff?
I've always seen xanthum gum listed in store bought products, but never knew what it was for. Again, if you wanna keep natural, I'd stick with the banana and oats. They both help with the thick and smooth part.
I'll fly in to CA and we can experiment with different ingredients to perfect the shake/smoothie. We'll have them for breakfast, lunch and dinner. (I'll provide the laxatives, if needed.)