Peggy, as I mentioned Digital ICE is for transparencies and negatives, not prints, so no, it wouldn't show much.
There is a difference between multi-sampling and multi-exposure in SilverFast. Multi-sampling is just that. It re-scans the image for the number of times in succession that you set it for and then averages the results, which reduces grain and artifacts. Multi-exposure is different insofar as it scans twice at two different exposures: one intended for highlights and mid-tones, and the other for bringing out shadow detail. IF however you are using a high dynamic range scanner, if the scanner picks-up all the shadow detail it can without using multi-exposure, you won't see much difference with multi-exposure. But on scanners with less dynamic range, logically it should show merit. On an Epson V700 for many images you won't see much difference of shadow detail quality with versus without multi-exposure, but for some images there may be some visible improvement.
SilverFast is scanner-specific - has nothing to do with your printer.
The main differences between the V700, and the V750 are that the latter has a glass bed for wet-mounted scanning, the higher-end version of SilverFast, and what Epson calls "high-pass optics", which they say consists of anti-reflective lens coatings and a high-reflection mirror providing what they claim to be the highest level of image quality and faster scans. I have not personally been able to test the difference of results between the two models. There is quite a price difference between them.
In your capacity as a perfectionist, I agree - you cannot just throw a slide onto a scanner, use default settings and expect the best results. I find I generally need to tweak each image.