Shouldn't be any problem with the open holes, but you could tape over them if you're worried about dirt, aerodynamics, or whistling noises. As a matter of fact, running fewer spokes on the non drive side will probably even out the spoke tension between the two sides. It will be a little more challenging to true, though.

That being said, is it really worth the hassle? You will be saving about 40 grams by doing this.