Really depends on your individual circumstances, the uni course you're going into or job you're applying for. Some care, some don't. Some uni courses don't have interviews..
From a general uni perspective, I don't think it really matters regarding school leadership unless you're either applying for a scholarship or interviewing for entry.
I think any extra-curricular activity is better than no activity..... just in general.
Again, see first sentence. Perhaps providing some further information (e.g. job/uni course) would help a better personalised answer
