Not likely. Southwest has been profitable in every year of its existence, except one, and that's 31 years. I don't know about Jet Blue.
You've got a burr under your saddle about SW, for some reason.
Yep. Southwest pilots are represented by the SWAPA. Flight attendants by TWUA, at least around here. Mechanics are union too, but I think they farm out a bunch of stuff to third parties that might not be... I don't know what union but you can look here:
http://www.iflyswa.com/careers/mxapmech.html
if you want to see it yourself. Scroll to the bottom where it says "Union position. Union dues required."
Unions have air transport sewn up. Seriously.
I don't know Jet Blue. I'd be surprised if their pilots aren't unionized...