QUOTE(tekplyrX @ Jun 6 2013, 05:49 PM)
He joined the night's watch because that was most likely the best option for him. especially since stark men have been known to join the night's watch of their own will in more recent times. Catelyn hated him so much she probably wouldn't have let him prosper. He would most likely never own lands or titles, unless ned stark or maybe their sword master (the guy theon killed) knighted him he would probably never be a knight. Being the "*******" of Ned Stark, the most honorable man in the 7 kingdoms wasn't helping matters as well. If Ned Stark had been like Robert Baratheon or some other character whom didn't care so much for honor then he might have had a slim chance of making something of himself without his "father's" single act of dishonor clouding over his head all the time.
Catelyn was just a selfish and impulsive character who did things the way she wanted. If she had left the whole "tyrion's knife" issue to ned stark NONE of what happened to them would've happened (but then again the story might have not been this interesting

) and sadly most of the kids took after her (robb especially) attitude wise.
I don't doubt joining the Night Watch was one of the better options for him at that time. But the order was probably at its lowest point when he joined them. It was recruiting peasants, petty criminals and rapists. The standard was so low that most of Westeros see the Night Watch as a form of punishment. But you do bring up good points about his rather limited alternatives. I wonder tho if Robb had the power to knight or legitimize Jon in some ways had Jon been there with his brother.
In regards to Cat, i think it's a bit harsh to describe her as only selfish and impulsive. Sansa in season 1 is perhaps someone that matches the description. As i've said earlier, she was driven by her maternal instincts and a sense of duty to protect her children. Her decisions affected people and events but her motivation had always been pure. I don't necessarily agree with her actions but i respect her intent.
I know a lot of people feel the war resulted from Cat's decision to kidnap Tyrion but i disagree. The war was always inevitable. A lot of other things were already in motion despite her actions. Cersei was always going to kill Robert one way or another, just as Ned would have kept following the trail and eventually discover Joffrey's bloodline. Once Joffrey becomes King, all bets are off.