confused?

I feel as if my stance is all over the place at the moment as i seem to have gone from boxing from quite a square stance like where my jab was coming across my body to the middle but then i changed to a more narrow stance where my jab is longer.But instead of sticking to one or the other i seem to be kinda stuck in no mans land where im not quite either.I feel as if they both have there advantages.Should i stay long when im on the outside keep my opponent at the end of my jab and stand more square once im inside to get better leverage on my hooks.Do most fighters fight with two distinct stances one for inside fighting and one for outside?

I think you should be more square on the inside and narrow on the outside. I'm no expert though. Personally, I like keeping narrow all the time.

I always feel unsure as to how far across my jab should come so my shoulder protects my chin,Should it be a case of my shoulder coming across to protect my chin or tucking my chin in behind my shoulder?
Maybee i could explain myself better if i put it like this...If i stand parallel feet shoulder withdth apart and just punch straight out in front,I think this is like they do in karate,Is it the same thing when im trying to achieve in my boxing stance with my straight jab and right?