However, what I think should bother people is blatant intent of the actual survey, and what that would seem to mean as far as what the student will learn. For instance, question number one is "The government should encourage rather than restrict prayer in the public schools" and then offers choice of L or C. How is that for a loaded and leading question, as if those are the two choices. I don't believe that the government has any authority to restrict any prayer anywhere, but neither do they have any role in encouraging it. This question implies a statist position by suggesting that in all cases it is the government that should dictate when we pray, or when we do not. It very clearly comes from a position of seeing the state as the prime mover in matters of belief and faith, and that is insidious.
I agree with your second paragraph
Plausible deniability. The school knows that a student's "social circle" that includes the over 40 demographic is going to be that of close relatives, parents mainly. Normal kids wouldn't pester a neighborhood adult with this kind of junk anyway. That's what family is for.
Soviet Bloc teachers were expert at keeping their eyes and ears alert for rogue anti-government minded parents. Parents were afraid to speak in their own homes within earshot of their children, as the state had ways of discovering unapproved value systems via innocent kids.
The school sent this little survey home. Maybe the cluelessness is so pervasive that it's just that easy. Otherwise, they won't make that mistake again.