After looking through the help file to find anything about the camera response curve settings under "Merge to HDR" I gave up,
and now I'll give it a shot here:

Should this just be on automatic? Is it even necesarry with only merging raw files?

How do i calibrate my camera? how do i get these response curve files? Should I make them myself or get them from the camera manufacturer?

When would a custom response curve be needed instead of just using the "automatic" setting?

thanks in advance for any help