You can use a combination of Activator and FlipControlCenter. Use Activator to reassign a long press of the power button to "do nothing" on the lock screen. FlipControlCenter will allow you to disable the airplane mode and wifi buttons in Control Center on the lockscreen.
Not quite as elegant as a password, but if you misplace your phone it should prevent it from being shutdown or airplane mode enabled.
Amazing, thank you for your help.