reliance on expert, internal auditor and component auditor

Hello dear tutor... I hope that you are well... It is necessary for auditors to do these before place reliance on expert's works: 1-assess his objectivity and independence(eg:by considering the reasonableness of fee paid to him-the more independent person,the more reliable work) 2-assess his competence and qualification( more competent person means more reliable work) 3-agree scope of work at start(any deviation from this agreed plan will reduce the reliability of his job) 4-evaluate the relevance and adequacy of his work( reasonableness of assumptions used, reliability of sources of data ,...) Now this is my question: Q1:should we(as external auditor) evaluate the same things before reliance on internal auditor?(or we should consider other factors) Q2:should we(as group's principal auditor) evaluate the same things before reliance on component auditors?(or we should consider other factors) Thank you in advance