How much higher in temperature would an HDD be when being used for gaming purposes? About 10c? or much more?
Just a bit worried if the array could be getting to dangerous temps.
I'm not sure what you mean by this. The only thing that would affect the temperature of the HDDs is the GPU heat. HDDs don't work harder in gaming than they do in, say, transferring large files, so they don't heat themselves up. They do last longer, though, at lower temps.
Could you describe your entire case/fan setup in greater detail or provide a picture?