If the OBDGenie has been programmed and got a green light, then programming is not necessary moving forward. The hardware can be installed before or after running the programmer. However, running the programmer first may result in trouble codes or errors on the cluster referencing the blind spot monitoring kit, because the Body control module cannot communicate to the hardware.
If there is an error message for a tail light out, then there could be an issue with the tail light harness included in the kit, or a fuse/relay was blown during the installation of the tail lights. Sometimes this can result in the turning signal rapidly blinking when the turning signal for the affected side of the vehicle (tail light) to reference if it's the passenger or driver's side.