It will be like flashing the micro controller with a code which will take a set of RAW images when started and transfer it to PC and then shut down.
You can take raw images and transfer to PC and shutdown use CHDK.
Note if the camera is completely inaccessible, you will need some way to power it on, either:
1) Arrange some way to physically press the power or play buttons
2) Physically replace the power with some external control
3) Arrange for the power button to be permanently held down, and control the power supply externally. This method works on most cameras, but I'm not aware of it being tested on sx530.
The focus and exposure settings will be kept constant at optimal settings.
Setting fixed exposure and focus distance should be no problem.
Can the current port of SX530 be used for RAW file transfer to PC with or without saving on SD card?
Yes, either one. On this port, jpeg will always be saved to the card.