You’ve got yourselves an absolutely marvellous event. Well done to every single person involved.
I can only reiterate what people have already said. I have taken part in many of these type of events and your first challenge is up with the best already.
I cannot offer any advice on how to improve, but, as a slow runner, I totally agree with the comments about not turning this into a race to satisfy speed merchants.Please keep it as a primarily walking event where runners are welcome. Also, as somebody has suggested, please don’t incorporate a shorter route. there are plenty of shorter events around. keep it exactly as you have and please send me next years entry form, I would like to take part in this excellent event again.