I suggest that you try making the luminance adjustments with the curves tool rather than all those other adjustments. You can make seperate adjustments for each color with curves (if you want to do so).
Digital Gem should be used only very rarely for very rough negatives.
The 40 20 6 Unsharp Mask settings are pretty extreme. John Shaw, in the article I mentioned, recommends Unsharp Mask settings to offset the minor softening effects that Ice produces. Ice should not be used unless necessary to eliminate scratches, etc. since it does soften the image a bit.
Some tend to use the scanning software as an editing tool. That is not a good idea. It is far better to use the scanning software only to get a good clean scan and do the editing with an editing program.