according to the teacher feedback:
Question 2: the answer is a no, unless you are sure that someone with learning difficulties is actually going to be one of your interviewees.
Question 4: again, another no, unless you are targeting children, sick patients in hospitals etc as interviewees. Minority groups providing basic needs to their families are not vulnerable groups.
Question 10: again, answer must be no. You will be very careful to avoid that any harm would be caused to you and others by for example avoiding venues where there is the risk that accidents might occur or any issue of safety would make it too risky for you and others to meet your interviewees there (by for example meeting a particular respondent in safe environment or online).