Heinrich, you have created a well-intended safety survey, but IMHO miss an important aspect which may bias your results.
Human attitudes can be influenced by the situation – the context of the task.
An SOP could be acceptable in one situation, but the same situation (requiring the same SOP) but in a different context, the SOP’s use might be judged quite differently.
Similarly, some people do not make clear distinction between SOPs and checklist drills – often interchanged, and whether the SOPs are provided for guidance or as mandated action.