질문드립니다

선생님 독해의신2 지문 112번이구요

We found that the children with ADHD were less compliant with their parents' instructions than the other children were , and this was especially apparent during the work period. For now, suffice it to say that this finding has been confirmed in many other studies done more recently.

suffice it to say ~ 에서 suffice가 여기서는 자동사적으로 쓰인것 같은데

주어 역할을 하는 it / to say~가 긴 주어라서

suffice 뒤로 갖다놓은 구조로 봐도 될까요?

그리고 수일치가 suffices가 아니라 suffice로 되어있는데

주어가 살아있는 명령문인 구조로 봐도 괜찮을까요?