The 1st shot is certainly not sharp enough, the 2nd - maybe ... looks like it could stand a little more USM.
In terms of contrast, I think you are actually getting a pretty good scan - this is a high contrast situation after all, but it needs a little toning down in PS to provide a pleasing image. I think the highlights have been correctly captured, which is the most important thing - all you need to do is use level or curves to bring out the shadow detail a bit ... the shadow detail appears to be present (its not solid black) but it is a bit dark.
The distinction between a "bad scan" and "bad post processing" is often difficult to determine, and you can spend hours playing with scanning settings to no avail when 5 minutes in PS would do the trick - conversly, no amount of playing around in PS can salvage an incorrectly scanned image!
So how do you tell what went wrong where? The critical thing with a scan is to get the white and black points correct - nothing else really matters. If the scan has highlights just touching pure white, and the darkest shadows just touching pure black, you are in good shape - but note that scanners can be fooled by scratches and dust which generate false white and black points!
Also keep in mind that your image may not have any true highlights or shadows - your scanner doesn't know this, and assumes the brightest part of the image is white, the darkest black - this again will distort the scan and you must make allowances.
Anyway, once you've got your scan with correct highlights and shadows, the distribution of brightness throughout the rest of the image is best handled in PS using the curves and levels.
The most common mistake I see with an image such as yours is trying to create a brighter image by scanning it for greater exposure - all this does is burns out the highlights and create very grainy, washed out shadow areas.
If you don't want to use PS (or similar), you could increase the gamma setting (now I think incorrectly labelled "brightness" ) in Vuescan, but levels and curves in PS is a better method.
Oh yes, by generating 16 bit scans you will have more scope for tone adjustments (as the software has more data to play with) - convert to 8 bit only when you have to.
Colin K. Work, Pixstel