Running the explorer shell as Basic User

I wanted to force applications to run by default without administrator
rights, from within an admin account. DropMyRights and SetSAFER dont do what
I want. MakeMeAdmin will not allow me to use the Run As... context menu, only
the specific shortcut.

So I'm forcing the shell to start as Basic User. I've enabled Basic User by
creating this reg value
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Safer\CodeIdentifiers]
"Levels"=dword:00020000

Next, I used the instructions at
http://msdn.microsoft.com/en-us/library/ms838576.aspx ro change the shell to
%SYSTEMROOT%\system32\runas.exe /trustlevel:"Basic User"
%SYSTEMROOT%\Explorer.exe
At first I changed it in HKLM but I only got a common Explorer window, no
taskbar and no desktop. So I made the change to HKCU.

The problem is that the shell lacks the SeShutdownPrivilege so I cant do
anything power-related from the start menu except logoff. Then I can shutdown
properly. Using the Power/Sleep on the keyboard works fine, but if I set them
to ask what to do, only the log off option is available. I added the Everyone
group and my User Account to the shutdown privilege at secpol.msc but no
effect.