1. ) This is a point of debate as to whether a PPL will help you...if at all, it might help with your air sense during primary flight training, but not much after that.
2.) A pilot is a pilot, they are all in the Canadian Forces.
Technically, there is no Navy, Army or Air Force, just Maritime Command, Land Forces Command and Air Command.
That said, all pilots fly aircraft as part of Air Command. There are two groupings that do not directly support Air Command's own mission (NORAD, SAR, tpt, etc...), the maritime patrol & helicopters - primarily in support of Maritime Command (Navy) and tactical aviation (helicopters) - primarily in support of Land Forces Command (Army).
A Sea King pilot is in Air Command, but operationally deploys on ship (Frigate, Destroyer or Replensihment ship) in support of Maritime Command's mission.
G2G