I'd say that work experience specifically within Politics is not always interesting, specifically if you were just helping an MP (I'm not entirely sure how relevant that is to study International Relations). Its fantastic that you've done so much but it would probably be beneficial to focus on the experiences where you felt you learnt something. That "something" would need to be either relevant to IR or being a Diplomat.
I say this because its better to express the value of the of the things you've done, whether personal (your multi-ethnic/ cultural family) or educational (the languages you've studied), rather than list all of the things you've done. It shows how deeply you care for your subject and why you wish to achieve your aspirations of being a Diplomat.
I was lucky enough to go to Talks, Debate club and other super-curricular events but I found myself writing about how my race, art, Political books, Podcasts and Political shows had deepened my desire to study Politics.
To reiterate my point for the last time, it is a good thing to widen your experience for IR but it is better to focus on deepening it. Why are you choosing these subjects, courses? Why are you mentioning your identity or your skills? Why does it matter beyond just getting into a good university?