Wow that is a weird combination of DTCs.
Pump prime reading is good and within specs. Low or high fuel pressure could cause the random misfire DTC P0300 so if you still have the fuel pump resistor bypassed then get that taken care of and the P0300 issue may get resolved.
For DTC P1380 are you having any known ABS issues? ABS light on or running with bad wheel sensors. This DTC triggers when the electronic brake and traction control module (EBTCM) has detected a malfunction which will not allow the EBTCM module to transmit rough road data to the PCM module. An ABS capable scanner should be used to further diagnose this issue.
The reason for low boost is the P1645 DTC. The PCM module has detected a malfunction with the boost control solenoid circuit. Possibility of wiring between the PCM module and boost control solenoid, bad boost control solenoid or PCM module.