Would you be worried if a large number of teachers seemed to leave a school in a relatively short space of time. DD1 is fairly new to school still so I haven't much experience of what is 'normal', but her school seems to have quite a high turnover of staff. Last year her teacher left at Christmas, and a larger number (half a dozen maybe) left at the end of the summer term, various reasons including retirement, adoptive leave, 'spending more time with family', new jobs closer to home etc. This year, both the year one teachers left at Christmas, and we have just been told that both the replacements (both NQTs) are leaving at the end of term (new jobs). Would this concern you?
The school has consistently struggled with OFSTED (previously satisfactory, now needs improvement as they have changed the description, same thing really) but I am reasonably happy with DD's progress, and she loves school (she would probably do better academically at a 'better' school, but would she be as happy?).