Ans in one word...1)A partner in crime 2)one who journey on foot 3)one who imitates the voice gesture etc of another 5) one who talk in sleep one who compiles a dictionary 6)one who collects coin

1.) sidekick

2.) pedestrian
3.) ventricalist? (I'm not sure if it's right or spelt right..?)
5.)?
6.)?

---Sorry, that wa sall that I could do...