lax, you're hearing some strong opinions from some folks who have had bad luck in the career. I've had great luck with it, and would encourage you to pursue it if it's what you want. Not everybody is a good fit for the job, and you'll be gone half the time, but I still think it's a worthy job, and I'd do it again if I had it to do over...even now. But that's just me.
You are in a special position because you have a great fallback with the law degree. You could give flying a try and if it doesn't work out, you have a great plan B.
I don't know how easy it would be to get the legal right to work in the US, so you might have a hard time getting hired here. If you did your training in the US, you'd have to convert to Canadian licenses to work at WestJet or Air Canada. You might be better off training in Canada.