Hi,
yes you can use it, here is the example:
HOWTO: S32 Design Studio - Create a New S32DS Project from Example
Without using S32DS, how can I flash my code to MPC target?
You can use any debugger interface which supports MPC57xx devices with JTAG:
For example PEMicro, Lauterbach, iSystem, PLS, GHS, etc...
Each of this has different steps for loading the code into micro.
or you can use serial boot mode via serial communication interface.
regards,
Peter