An update after discussing this issue with Intel;
"...The Desktop Utilities Version 3.2 is meant for desktop models, and not for NUC.
The NUC is considered to be more of a mobile model, and input voltage of 1,74 V is perfectly normal...".
The Desktop Utilities still seems to be a great monitoring tool, which can be run in W7 environment (and not in "BIOS mode").
Yes, that's correct, in fact, your processor is working under specifications, see the following information where you can find operating voltage on page 90 table 43,