Try:
1. boost pressure solenoid bypass -
viewtopic.php?f=98&t=64278&p=709322#p709322 - replace if needed.
2. check for proper movement of variable vane actuator rod - per GDE "You can check the vane functionality at idle in park. Underneath the vacuum actuator on the turbo is rod extending downward connected to the vane mechanism. If you pull off the vacuum line at the turbo, the arm should drop about 1/2 inch and then raise back up after reconnecting the vacuum line. It is a bit difficult to see the rod, but this is the easiest method to check for proper VGT vane movement." If not moving like it should you likely have sticky variable vanes. Usually 1 or more "italian" tuneups will fix this (on engine at operating temp do a full throttle run up a slight hill like an interstate on ramp grade)
Couple of other comments:
1. a noticeable turbo "lag" is common with the stock turbo - maybe 1/4-1/2 a second or so before the turbo kicks in.
2. "excessive" smoke varies between vehicles - normal smoke without a GDE tune looks like a gasser with really bad rings (darker of course) while truely excessive smoke begins to resemble a coal fired locomotive.
3. unrelated but have you a) read the NOOB guide and b) checked the airbox to turbo hose for a tear on the bottom just in front of the turbo?