I have used one of these cameras for only a few hours so I'm no expert, but the one I used was a friends and he emailed me with a couple of ideas I'll repackage for you.

Use the TIFF mode, 100 iso, and don't shoot at too wide an angle much as the lens in these cameras was known in some cases to display distortion at wide angles.

Be aware of a couple of issues with this camera, it applies some noise reduction to all images taken at less than about 1/30th of a second (from the specs in the manual) and there were cameras (early models) that exhibited red saturation in longer shots.

The night shot mode is the classic black frame subtraction and is mostly for use with the 'night light' feature. The red fuzzyness is either the red 'bloom' (saturation) or the camera stepping on the image with noise reduction/color correction. White balance except in daylight was apparently slightly questionable in these cameras under extremes.

Be aware that in a 30 second exposure, the stars are going to move.

Finally, in your editing software, is there a black point or color cast adjustment tool? The various flavors of software (Adobe Photoshop(various), Paint Shop Pro, etc.) have something that lets you select an area or point that should be black in the image. When this correction is made then you can see if the 'red' disappears.

Good luck and hope this helps a little.

Oh, when using a tripod make sure that the tripod is resting on a stable solid surface like concrete.
A deck, or balcony, or platform are not stable for long exposures, unless you don't move around much. A deck will bounce, a platform or balcony may 'sway'. You will never feel it, but the camera will see it.