I thought, a while back, that the Exit option (only useable in Windows) was removed from the project?
ive had to manually alter the nu2menu for the past 1 or 2 revs to add the option back in.
if you want to add it back just place the following code in the start menu area of the nu2menu.xml file as shown
CODE
<menu id = "start menu">
<MITEM TYPE="ITEM" VISIBILITY="@Shl(@FileExists(@GetWinDir()\setupldr.bin),'1')" CMD="EXIT">Exit</MITEM>
</menu>
as for the Shutdown and Restart options those are in the nu2menu.xml file and should work properly but i havent had the time to test them personally.