Hi, I did an EPQ
Choosing something too specific may be a concern but 5000 words is really less than you think (mine was 7000 words - whoopsie daisy and I had to cut 2000 words out which was PAINFUL)
I don't know anything about your topic but it sounds really interesting! Are you doing AQA? Because if you are,
you're supposed to change your question at some point. What I mean by that is you start by having some initial ideas and you talk about what they are, then you narrow it down to a specific question and then you do your mid-project review in like May/June (can't remember exactly) and that's when you decide your final question.
So chances are, the current question you have in mind, won't end up being your final question. If you are absolutely set on it however, when you do your mid-project review, you have to justify why your question has stayed the same from start to finish.
Hope that makes sense