I'd drop both the Crystal and Carapils, replace them with wheat and definitely use the rice hulls.
I agree that the IBU strikes me as high, but that's your bag; if you like hops, go fer it. With that hops schedule, you will obscure somewhat the ester profile from the yeast, but that's your decision. Personally I am not fond of hops in my Hefeweissen.
The lemon zest ought to add a yummy note!