With your waste gate arm unattached, you may be overboosting without realizing it. Do you have an aftermarket boost guage? I would suggest using a cotterpin, or in a pinch a paperclip to hold your flapper arm onto the actuator rod. This happened to mine, though I never hit fuel cut.
Compressing the spring on your boost controller will increase the psi you are able to boost to, can you take apart your boost controller to see whether you are compressing the spring?
Venting your BOV has shown to make DSMs run fairly bad alot of the time. Fix the above mentioned things, see what that does. How high are you turning your boost up to to hit fuel cut?