I think you're confusing the user vs administrator distinction with the userland-vs-kernel-mode distinction... but never mind...
Deliberately conflating, but not confused.
What I'm saying is that the "Ctrl+Alt+Del protects your password" claim is overblown; the suggestions you give only amplify that, as they are even more ways to circumvent it...
But none of them are trivial to do. Especially if I am not already an administrator on the system.
I can trivially run a program to throw up a screen that looks like the login screen on a PC at work. TRIVIALLY.
the "Ctrl+Alt+Del protects your password" claim is overblown
Its like door locks. Nobody anywhere claims they make your house secure, but it does stop people from being able to literally just wander into your house.
In the real world door locks prove to be highly effective at keeping people out of places. From hotel supply closets and building electrical rooms to the bosses office to your bathroom stall while your taking a crap.
Nobody here is arguing ctrl-alt-delete is some magical super thing, its just a door lock. But its enough of a hassle to get around, that its plenty to stop all kinds of casual intrusions and mischief.
Ctl-Alt-Delete is the same way.