Okay, you've got quite a bit to work with there - you just need to sex it up (as my dearest Ma would say).
Paper round - shows work ethic from young age, independence, motivation to work early mornings and therefore punctuality.
Working in the shop - till trained, comfortable dealing with stock and experienced with customer relations. You weren't 'sacked', you were let go due to your employer's difficult financial circumstances. Not your fault at all.
The above two show that you are able to work and study at the same time which demonstrates organisational skills and an ability to separate work and academia (providing you did well in school that is).
Volunteered in a variety of places centering around child education. Children can be unpredictable and working with them can be incredibly stressful at times, so this shows that you can cope with this. Also, you're the responsible adult around such children so therefore you handle responsibility well. You could also incorporate your unofficial first aid knowledge in here stating that you remain calm and level-headed when unfavourable circumstances arise.
I don't know what Outward bound is - but hopefully you'll get the idea from above.
Hope that helps.