I'm a mobile learning analyst and my job is to do just what the OP has mentioned. I have not found a way to remotely add a passcode to restrictions, everything else can be done with a link in an email or website being clicked on the device and saying yes a couple of times.
I want to believe the OP because I certainly do not know everything, but the passcode on restrictions, pretty much want to call BS. I can remotely lock restrictions, where everything is greyed out and you will no longer have access. But I have to have physical access to the device to implement a restrictions passcode.
PM me mercury7, I would love to check your device out.