Didn't read the entire thread, however, if you were to get a piggyback system such AEM F/IC or a Greddy Ultimate Emanage (personally I prefer this) for boost and maintain obd2, would be beneficial to you. What it does is trick/lies to the factory ecu in believe the factory A/F and timing setting is the same, when actual it intercepts the signal and swap it to your tuning specifications. It would still allow you to read through the obd2 port if any codes were to show. Also it another option as it may be due to fund reasons as well, many people do this and have had great gains in hp/tq.