2003 TrailBlazer LS?

A couple of questions if I may. First concerning the "Tattle Tale" / "SDM". Was Chevy stupid like a Fox by running the air bag actuation control through the SDM or will the bags still deploy if the SDM is unplugged??? If they will not work when unplugged, can another mating plug using jumpers be fitted to the harness to enable them to work without the Recorder working??? Second, what brand and or model code readers do U like & dislike & why??? As I am now disabled and this is the only machine I will probably ever work on with need for a code reader, that which I buy doesn't have to have all the bells & whistles, just get'er done! Tnx. John