Just installing the DP alone is enough to require a tune or for you to stay out of boost until you get one. If you were just installing the EWG, you would have been fine running the EWG off just spring pressure and you would need to disable the CEL that would be thrown by your stock BCS (I forgot the code #, but it relates to a sensor that measures the barometric manifold pressure. Maybe it was p108?).
Now maybe I misunderstood your intentions, so I will just assume you're planning on using the COBB stage 2 OTS map. Disconnect your stock BCS vacuum lines completely. I would still suggest the e-tune from Eric as that would be easy to flash on as soon as you install the parts and allow you to boost safely. I am currently using his stage 3 map with some custom tuning for an EBCS + MBC hybrid w/ the 38mm EWG and I friggin love it