re RAW(sony ARW) : you'd get a much better handle on post processing re noise and colors if you were using ARW/RAW.
your camera supports shooting both, JPG and ARW simultaneously, I assume.
Not sure about the availability of the software feature Long Exposure Noise Reduction on ARW if JPEG is turned on, as well, though.
Give it a try and see the difference in shooting result and postprocessing depth?