May I ask why the NAFTA visa is considered a free ticket? I understand that it makes it possible for Canadians to find work in the US, but some of my Canadian-born friends have tried this and it is not necessarily so easy. US employers need to prove why they can't hire a US citizen for the job, similar to LMIA here. After having no luck with this route a couple of my friends ended up marrying into the US instead.
I don't think so, you only need a valid job offer and your passport at point of entry to get the TN visa.
Job market in Canada is so bad that there are people who legit move here to get the passport and work in the US.
And I'm not talking about just Asian people, many Europeans/British people do it too.
Edit: there's a list of occupations that are eligible for this visa and if yours isn't on the the list then tough luck.
I'm assuming your friends are in a non stem background?