I have used raw wheat in Belgian Wits, at a higher percentage than your grain bill. The thing that makes it work is that the gelitinization temp of wheat is lower than the mash temps for malted barley. You have a bunch of enzymes from the 2-row, pils and malted wheat. This will convert with no problems.
Bob has given some good advice on the rice hulls, put some in and your sparge will be no problem. I just got several pounds of rice hulls to have around as "insurance".